KR860001652B1 - Moisture transmitting properties waterproof canvas and method for preparation thereof - Google Patents

Abstract

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Description

Breathable tarpaulin and its manufacturing method

1 is an electron micrograph of 2,500 times the micropores formed on the surface of the polyurethane film of the moisture-permeable waterproof fabric manufactured according to the method of the present invention,

2 is an electron microscope cross-sectional photograph at 250 times magnification of voids formed in the polyurethane film of the moisture-permeable waterproof fabric manufactured according to the method of the present invention.

3 is an electron micrograph magnified 400 times to observe pores and micropores penetrating the pores in the photograph of FIG.

The present invention relates to a moisture-permeable tarpaulin excellent in waterproof and moisture-permeable, and a method of manufacturing the same.

The human body is an energy generator that generates a certain amount of heat energy and water vapor by metabolism at all times.

In other words, in order to maintain a pleasant mood at all times, a balance of heat exchange between the generated energy of the human body and the human body's attention should be made.

From a physics standpoint, this balance should keep the skin temperature at about 34 ° C and always keep the surface surface humidity below 100%.

TABLE 1

Perspiration due to various activities of the human body

In order to satisfy these conditions, the amount of sweating as shown in Table 1 must be sufficiently released to the outside of the coating. For this purpose, the moisture permeability of the coated paper should be 5000-6000 G / m ² · 24hrs or more. .

In addition, it is necessary to keep warm in the winter, but to release heat and water vapor in the summer, so it was considered impossible to solve these two conditions with the same clothes or coated cloth.

In order to solve this problem, the waterproof coating method has been used as a breathable and moisture-permeable waterproofing material in the past, but since they did not properly balance the waterproofness, breathability and moisture-permeability, the waterproofing pouches manufactured by these methods are used for rain, sports, and leisure. When used as a garment, there were problems such as insufficient waterproofness, moisture permeability, and breathability.

Among the conventional methods, there are coating fabrics in which various foaming agents are applied to the polyurethane microporous coating or elastomer, or the microporous coating is formed by other methods. However, the former method uses a polar organic solvent solution of a polyurethane polymer on a textile fabric. Since the polyurethane polymer is wet-coagulated by coating and immersed in water to form micropores, moisture permeability and breathability can be easily provided, but it is difficult to obtain water pressure resistance.

There are various methods of the latter. One of the methods is breathable by dissolving the elastomer solution containing foaming agent on the woven fabric and decomposing it in the drying step to release carbon dioxide, nitrogen gas and oxygen gas into the elastomeric film. And a method of imparting moisture permeability, and another method is to add a solvent which is not mixed with the solution of the elastomer and apply the stirred mixture to a knitted fabric to form pores in the coating. It is a method of making pores in the elastomeric film by applying and drying the elastomer of the emulsion zone having a lot of bubbles.

After all, these three methods have the drawback that the water resistance is very poor because the pores are large and most of the independent pores are given to the air permeability and moisture-proof enough to be of practical value.

As described above, the conventional general waterproofing cloth is excellent in waterproof but not permeable, and thus sweat and inferiority emitted from the human body do not escape from the outside, thereby causing discomfort to a user wearing a garment made of such a waterproof cloth.

Therefore, at least 5000 to 6000 G / m ² · 24hr of water vapor transmission rate is required to solve such a conventional defect, but in order to obtain such a water vapor transmission rate by the conventional method, the size of the pores formed in the elastomeric film is at least 10 μ °, most of the time. If the pore size should be maintained at about 100μ ° accordingly, the water vapor permeability is good, but there is a problem in that water leakage cannot be prevented even if the elastomeric film surface tension is reduced to the minimum.

In order to solve the conventional problems, the present invention is to coat the solution containing the polar polar solvent solution, silica gel, surfactant and polyisocyanate on the fiber cloth, and then wet coagulation, forming micro-processing and appropriate treatment The purpose of the present invention is to provide a moisture-permeable tarpaulin having a good moisture permeability and waterproofness by drying and water repellent treatment and a method of manufacturing the same.

Hereinafter, the present invention will be described in detail.

The present invention provides 8 to 30% solids of polyurethane polymer, 0.1 to 10% of silica gel, 0.1 to 5% of bioactive surfactant, 0.1 to 5% of anionic surfactant, and 0.2 to 5% of polyisocyanate. 3 to 15% of the polar organic solvent solution was coated on the fibrous paper. M. After wet coagulation in F aqueous solution to form micropores, extraction with a polar organic solvent in an alkaline aqueous solution, elution of silica gel, and drying and water repellent treatment to prepare a moisture-permeable waterproof cloth having both moisture permeability and water resistance.

In the present invention, the size of the pores formed on the surface of the polyurethane polymer coating is mostly 0.1 to 3μø, the average density of the pores is more than 20 million pieces per 1 cm ² , a number of fine pores having an average size of 20 to 50μø inside the coating layer A plurality of micropores formed between the pores and the walls between the pores are formed in a size of 0.5 to 5 μø, and the distribution density thereof is about 250 times the average density of the micropores on the surface of the coating (about 5 billion / cm ² ). It becomes abnormal. In addition, the present invention harmonizes well with pores of relatively large pores formed in the surface of the polyurethane polymer film under 3μ, and also fine pores, pores, and micropores penetrating between the walls of the pores are silica gel, water repellent and poly By bonding to each other with isocyanate or the like and exhibiting superior hydrophobicity than the hydrophobicity of the urethane polymer, it is possible to obtain a moisture-permeable waterproof cloth having excellent water resistance, moisture permeability, and flexibility.

The moisture-permeable moisture-proof cloth produced in the present invention has a water resistance of 1000 mmH ₂ O / cm 2 or more, a moisture permeability of 5000 G / m 2 · 24 hrs or more, a breathability of 500 sec / 100 cc or less, because the micropores have the above-described structural characteristics. It is a moisture-permeable waterproof fabric, characterized in that the peeling strength is at least 100G / cm.

The silica gel used in the present invention uses a hydrophilic amorphous silica gel, and the silica gel in the polyurethane microporous membrane is extracted in the alkaline aqueous solution, which is the DM extract step, and the silica gel contained in the microporous membrane is The microporous coating forms a hydrophilic coating due to the silica gel remaining in the microporous coating due to a large number of micropores between the pores and the pores by eluting 20 to 70%. As the water repellent is combined with the hydrophilic silica gel in the microporous membrane to convert the hydrophobic silica gel into a hydrophobic silica gel, the water-repellent agent is formed in the post-treatment step to form a very strong hydrophobic membrane having excellent durability and excellent moisture permeability and waterproofness.

In the present invention, if the residual amount of silica gel remaining in the microporous coating after silica gel elution is 30% or less, that is, when the amount of the elution is 70% or more, it is difficult to obtain a strong hydrophobic microporous coating, the water resistance is inferior, and the residual amount of silica gel is 80% In the case of the above-mentioned, that is, when the amount of elution is 20% or less, the number of micropores penetrating between the pores and the pores is low, and the moisture permeability is low. In addition, in the present invention, when the amount of silica gel is less than 0.1%, it is difficult to obtain a strong hydrophobic microporous film, which may cause leakage due to water pressure, and when the amount is more than 10%, the strength of the micropores decreases and the micropores are too much due to the alkali solution. It tends to grow.

On the other hand, as polyisocyanate used for this invention, it is a compound which has 2 or more isocyanate groups, such as diisocyanate and triisocyanate. 2,4- (2,6-) torylene diisocyanate, diphenylmethane 4,4-diisocyanate, 1,4-naphthalene diisocyanate, isophore diisocyanate, hexamethylene diisocyanate or

(Diisocyanate) (triol)

Etc. are used. In addition, in order to stabilize the isocyanate group of polyisocyanate, it may block and use it with phenol. Here, polyisocyanate improves the binding force of the water repellent agent and the silica gel-based polyurethane polymer film in the post-treatment step, imparts durability and water repellency and oil resistance (CREASE-FLEX-RESISTANCE), and adhesion of the polyurethane polymer microporous film to the woven fabric. To improve. According to the present invention, when the amount of polyisocyanate is 0.2% or less, the effect is insufficient, and when 5% or more, the effect is excellent but the touch is worse.

As the type of surfactant used in the present invention, a nonionic surfactant and an anionic surfactant are used, and the nonionic surfactant uses a copolymer of ethylene oxide and propylene oxide as shown in the following scheme.

(Here x = 20 to 40, y = 10 to 80, PO is a propylene oxide chain and EO is an ethylene oxide chain.)

The above-mentioned nonionic surfactant is contained in the above-mentioned polyurethane polymer solution to increase the compatibility of silica gel, polyisocyanate, pigment and other additives, and to extract the polar organic solvent in the polymer solution in the coagulation bath and the coagulation bath. It controls the rate of osmosis or diffusion of water into the polyurethane polymer polar solvent solution, forms pores of the polyurethane film finely and uniformly, and smoothes the surface.

In the present invention, when the content of the nonionic surfactant is 0.1% or less, the effect thereof is insufficient, and when the content of the nonionic surfactant is 5% or more, the micropores are coarse and the water repellent is difficult to contact the inner wall surface of the micropores in the post-treatment step. There is a fear that the water repellency is lowered due to the lack of bonding with the polycyanate and water leakage.

In the present invention, the anionic surfactant uses a sulfonate prepared by the following reaction formula.

(Where R = C _n H _{2n + 1} and n is 12-15)

Anionic surfactants, like nonionic surfactants, increase the compatibility of the additives added in the polyurethane polymer polar organic solvents, and solidify the microporous wall surfaces that penetrate between the void walls and the pores, as well as the surface of the microporous coating of the polyurethane polymer. It speeds up and allows the polar organic solvent to diffuse quickly into the coagulation bath in the microporous coating. If the content of the anionic surfactant is 0.1% or less, the effect is insufficient. If the content of the anionic surfactant is 5% or more, the pore formation becomes large and the waterproofness is insufficient.

In the present invention, the polyurethane polymer is a polyester-based or polyether-based urethane polymer. The polyester-based polyurethane polymer has a terminal alcohol group and has a molecular weight of 1500 (adipic acid, 1,4- Condensation polymerization of butanediol and ethylene glycol), diphenylmethane-4,4'-diisocyanate, and dihydroxy compound to obtain a polyether-based polyurethane having a terminal alcohol group with a molecular weight of 2000, It is obtained by polymerization with diphenylmethane-4,4'-diisocyanate and diamine compound.

Generally, when the polar organic solvent solution of the polyurethane polymer is solidified in water, the microporous coating of the polyurethane polymer has a correlation between the amount of the polyurethane polymer and the diameter of the formed micropores, and thus the surfactant or silica gel used in the present invention. Although the correlation was alleviated due to the effect of, it is difficult to form the diameter of micropores less than 3μ when the content of polyurethane polymer is 8% or less, and fine pores can be obtained when more than 30%, but the moisture permeability is low. It feels like rubber.

As the polar base material used in the solution of the polyurethane polymer in the present invention, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, and the like are polar organic solvents. Moreover, it is the aqueous solution containing 3 to 15% of polar organic solvents in a coagulation tank.

The coater that can be used to manufacture the moisture-permeable waterproof cloth of the present invention is a knife-over roll coater (KNFEOVER-ROLL COATER), a reverse roll coater (REVERSE-ROLL COATER), and a coating machine that can adjust the thickness as a general coating machine.

In the present invention, the alkaline aqueous solution in the DM extract and the silica gel elution tank exhibits moisture permeability and water resistance along with the water repellent treatment in the post-treatment step by eluting an appropriate amount of the silica gel contained in the microporous coating of the polyurethane polymer. In order to achieve this purpose, a DM fabric and a silica gel are eluted by immersing a woven fabric in which a polyurethane polymer film is solidified for 2 to 40 minutes in an extraction tank maintained at 0.1 to 5% alkaline aqueous solution at 20 ° C. to 70 ° C. Here, when the concentration of the alkaline substance is 0.1% or less, the temperature is 20 ° C or less, and the immersion time is 2 minutes or less, the amount of silica gel contained in the microfilm is low and the moisture permeability is low and the concentration of the alkaline substance is 0.1. If the temperature is 70% or more and the immersion time is 30 minutes or more, the amount of silica gel contained in the microporous film is small, so that even if the water repellent treatment is performed in the post-treatment step, it is difficult to obtain a strong hydrophobic microporous film. There is a possibility that the lowering and hydrolysis of the polyurethane polymer are caused.

The post-treatment step of the present invention is to convert the microporous membrane of the hydrophilic polyurethane polymer into a hydrophobic microporous membrane having excellent hydrophobicity by the interaction of the water repellent agent, silica gel and polyisocyanate as a water repellent agent. As a fluorine-based water repellent

(Where x is an integer of 2 to 17, y is an integer of 0 to 4, Z is -H or -CH ₃ , M is H or F, n is the degree of polymerization), and as a silicone-based water repellent, dimethyl polysiloxane (Dimethylpolysiloxane) and methylhydrogenpolysiloxane. As the water repellent treatment method, the solid content of the water repellent agent is 3 to 10%, and the pad-dry-cure method is treated in the same manner as the conventional method, and isopropyl alcohol is also used in combination.

Examples of the material used in the present invention include natural fibers such as cotton, silk and wool, chemical fiber polyamides such as cellulose and viscose rayon, synthetic fiber knitted fabrics such as polyester and polyacrylonitrile, mixed knitted fabrics thereof, or short fibers. In this case, fine hairs are softened or reduced by a processing method such as calendering.

Thus, the moisture-permeable waterproof cloth prepared according to the present invention has a surface as shown in the photographs in FIGS. Because of its excellent durability, it is used in a wide range of sports and leisure wear, such as golf wear and ski wear, winter clothes, raincoats, and shoes.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

70d nylon fabric (inclination density 120ol / in, weft density 90ol / in) was immersed in an aqueous solution of 5% concentration of fluorine-based water-repellent agent and heat-treated at 170 ° C.

The composition of the A resin amount The composition of the A resin amount

Polyester polyurethane 16 parts HO (EO) ₁₀ (PO) ₃₀ (EO) ₁₀ H4 parts

67 parts of DMF polypropylene sulfonate 2 parts

Silica gel 7 parts 2,4- (2,6-) torylene diisocyanate 4 parts

250 g / m ^{2 was} applied using a knife over roll coater and 5% DM solution was immersed in a coagulation bath kept at 20 ° C. for 5 minutes, and then 2% sodium carbonate solution was extracted for 20 minutes in an extraction tank kept at 60 ° C., and sodium carbonate was removed. Washed with water and dried at 150 ° C. for 2 minutes.

This forge (a) in aqueous solution

It is immersed, the pick-up rate is 30%, and then heat-treated.

Comparative Example 1

250 g / m ² of AA resin solution was applied to one side of the nylon fabric water-repellent treated in the same manner as in Example 1 using a knife over roll coater, and 5% DM solution was immersed in a coagulation bath kept at 20 ° C. for 5 minutes, Extraction was carried out for 20 minutes in the extraction tank maintained at 60 ℃ and then dried for 3 minutes at 150 ℃.

The water repellent was treated in the same manner as in Example 1.

The results of measuring the physical properties of the samples prepared by Example 1 and Comparative Example 1 are shown in Table 1.

TABLE 1

Example 2

The polyester cotton short-fiber blended fabric was immersed in an aqueous solution of 3% concentration of fluorine-based water-repellent agent and heat-treated at 150 ° C.

Apply 300g / m2 with a reverse roll coater, immerse 2% DMP aqueous solution in the coagulation bath maintained at 20 ° C for 10 minutes, extract 3% sodium hydroxide solution into the extraction tank maintained at 60 ° C, and wash with sodium hydroxide to 130 ° C. Dry for 3 minutes at. (2) To the aqueous solution

Dip to 40% pickle rate in padgle and heat treatment.

Comparative Example 2

BB resin solution was applied to one side of the polyester cotton short fiber blend fabric pretreated in the same manner as in Example 2.

300 g / m 2 was applied with a reverse roll coater, and a 2% DM solution was immersed in a coagulation bath maintained at 20 ° C. for 10 minutes, extracted in an extraction bath maintained at 0 ° C. for 30 minutes, and dried at 130 ° C. for 3 minutes. Defoamer was dehydrated in the same manner as in Example 2.

The results of measuring the physical properties of the samples prepared by Example 2 and Comparative Example 2 are shown in Table 2.

TABLE 2

Example 3

Gradient-coated acrylic resin on 75d polyester fabric (inclination density 120ol / in, weft density 90ol / in) with gravure roll and C resin solution on one side

Apply 200 g / m2 with a knife over roll coater and immerse 4% DM solution in a coagulation bath maintained at 20 ° C. for 7 minutes, and again extract 2% sodium hydroxide in an extraction tank maintained at 30 ° C. for 20 minutes, and then wash with sodium hydroxide. Dry at 120 ° C. for 2 minutes.

To positio (a) aqueous solution

It is immersed, the pick-up rate is 30%, and then heat-treated.

The result of measuring the physical property of this sample is shown in Table 3.

TABLE 3

As described above, the moisture-permeable water-repellent foam prepared in accordance with the present invention is not only good in touch, excellent in water resistance and moisture permeability, but also good in breathability and durability, and can be effectively used in various sports clothing, winter clothes, waterproof clothes, footwear, etc. It is a tarp

Claims (17)

Polar organic solvent solution containing 8 to 30% of polyurethane polymer, 0.1 to 10% of silica gel, 0.1 to 5% of nonionic surfactant, 0.1 to 5% of anionic surfactant, and 0.2 to 5% of polyisocyanate The coated knitted textile forge was wet-coagulated with DM solution, and extracted with polar organic solvent in alkaline aqueous solution, eluted silica gel, followed by drying and dehydration treatment. The water pressure was 1000mmH ₂ O / ㎠ or more and the moisture permeability was 5000G / ㎡. A moisture-permeable tarpaulin with a film layer on which polyurethane micropores with a thickness of 24hrs or more are formed. The tarpaulin of claim 1, wherein the waterproofness is not lowered to 100% or less. The tarpaulin of claim 1, wherein the air permeability is less than 500 sec / 100 cc. The tarpaulin according to any one of claims 1, 2 and 3, wherein the peel strength is 100 g / cm or more. The tarpaulin according to any one of claims 1, 2 and 3, wherein a plurality of micropores having a diameter of 3 mu or less exist on the surface of the polyurethane microporous coating. 6. The degree of waterproofing according to claim 5, wherein the diameters of the micropores and the perforated pores formed on the surface of the film in the microporous film are formed in a range of 20 to 50 mu. The tarpaulin of claim 6, wherein a large number of pores are formed in the microporous coating, and the distribution density of the micropores penetrating the pores and the pores is at least 250 times higher than the distribution density of the micropores formed on the surface of the coating. The tarpaulin according to claim 7, wherein a large number of pores and micropores penetrating the pores are present in a number of 5 mu or less. Polar organic solvent solution containing 8 to 30% solids, 0.1 to 10% silica gel, 0.1 to 5% nonionic surfactant, 0.1 to 5% anionic surfactant, and 0.2 to 5% polyisocyanate Was coated on a fiber cloth, and then wet coagulated in a DM solution to form micropores, polar organic solvent extraction was carried out in an alkaline solution, and silica gel was eluted, followed by drying and dehydration to form a microporous film. The method of manufacturing the moisture-permeable tarpaulin made with. 10. The method of claim 9, wherein the silica gel is amorphous and using hydrophilic silica gel. The method according to claim 10, wherein the microporous membrane containing silica gel is solidified and extracted in a DM extracting tank of an aqueous alkaline solution to elute 20 to 70% of the silica gel. 10. The process according to claim 9, wherein the nonionic surfactant is made using a compound of formula (I). HO (EO) _{y / 2} (PO) _x (EO) _{y / 2} H... (Ⅰ) Where x is 20 to 40 and y is 10 to 80. 10. The process according to claim 9, wherein the anionic surfactant is made using a compound of the general formula (II). ROSO ₃ Na... (Ⅱ) Where R is C _n H _{n + 1} and n is an integer between 12 and 15. 10. The process according to claim 9, wherein the polyisocyanate is using diisocyanate or diisocyanate system. The method according to claim 9 or 11, wherein the concentration of alkaline substances in the DM and silica gel extraction tank is used using an aqueous solution of 0.1 to 5%. The method according to claim 15, wherein the temperature conditions in the DMF and the silica gel extraction tank are maintained at 20 ° C to 70 ° C. The method according to claim 15, wherein the immersion time in the DM and the silica gel extraction tank is set to 2 to 40 minutes.

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