JPH0544168A - Moisture-permeable waterproof fabric and its production - Google Patents

Abstract

PURPOSE:To obtain easily and stably the title fabric provided with excellent moisture permeability without impairing physical properties such as waterproofness and touch feeling, to be used as a raw material for raincoat. CONSTITUTION:A base material 1 is successively laminated with (A) a undercoating layer 2, a thin film consisting of crosslinked polyurethane resin's wet porous form with its weight being 5-15g/m<2> on a resin solid basis and (B) a facing coating layer 3 consisting of a polyurethane resin's wet porous form, thus obtaining the objective waterproof fabric. Specifically, the production process is as follows: a base fabric 1 is coated with a high-viscosity water- miscible organic solvent solution of polyurethane resin containing a crosslinking agent so as to be 5-15g/m<2> in the amount to be coated on a resin solid basis, and the resulting surface is coated with a low-viscosity water-miscible organic solvent solution of polyurethane resin. The resultant laminate is then immersed in water to coagulate the polyurethane resin followed by heating and drying to form both the undercoating and facing coating layers simultaneously to effect unification with the base fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-permeable waterproof cloth and a method for manufacturing the same.

[0002]

2. Description of the Related Art Breathable waterproof cloth is used as a material for rain clothes, ski wear and the like. In particular, when used as a material for rain clothing, in general, not only practically sufficient waterproof property but also physical properties such as moisture permeability and soft texture are required.
As a breathable waterproof cloth used for the material for rain clothing,
Rubberized cloth, urethane coated cloth, acrylic coated cloth and the like are known. However, all of these materials have particularly poor moisture permeability and have the drawback that they are apt to be worn when worn as a rain garment, and the discomfort during wearing is unavoidable. After that, for the purpose of improving the moisture permeability, we propose a moisture-permeable waterproof cloth with a structure in which a dry subbing layer made of polyurethane resin and a subbing layer made of polyurethane resin to be wet-coagulated are sequentially laminated on a base fabric such as woven cloth. Has been done. This moisture-permeable waterproof cloth is a coating film (resin) formed by first applying a composition obtained by adding a water-soluble substance (for example, salt, sugar, mirabilite, sodium glutamate, gelatin, etc.) to a polyurethane resin on a base cloth and then drying it. Then, a solution of a polyurethane resin to be wet-coagulated is applied onto the coating film, and then the whole is immersed in water to dissolve and remove the water-soluble substance in the coating film layer to form a porous film. Is formed, and at the same time, the polyurethane resin of the coating film formed thereon is wet-solidified to form an upper subbing layer, which is produced.

[0003]

However, even the above-mentioned moisture-permeable waterproof cloth in which the undercoat layer and the overcoat layer are provided on the base fabric is not yet satisfactory in moisture permeability, and is made of polyurethane resin. Due to the presence of the dry subbing layer, there is a problem that the texture becomes hard as a whole. Even during its production, since the water-soluble substance is fine particles, it is difficult to uniformly disperse it in the polyurethane resin, and the mixing work for that purpose is complicated and time-consuming. Moreover, since it is difficult to uniformly disperse the water-soluble substance in the resin as described above, the fine pores formed by dissolution and removal of the substance and the distribution of the pores must be non-uniform. , Was inferior in quality stability. The present invention has been made to solve the above-mentioned drawbacks of the prior art, and a moisture-permeable waterproof cloth having excellent moisture permeability without impairing physical properties such as waterproofness and texture, and a moisture-permeable waterproof cloth thereof. It is an object to provide a manufacturing method for obtaining.

[0004]

A moisture-permeable waterproof cloth of the present invention is a moisture-permeable waterproof cloth obtained by sequentially laminating an undercoat layer and an upper coating layer comprising a wet microporous body of polyurethane resin on a base cloth. The subbing layer is a thin film made of a wet microporous body of a polyurethane resin crosslinked with a crosslinking agent and having a basis weight of 5 to 15 g / m ^{2 in} terms of resin solid content. Further, the method for producing a moisture-permeable waterproof cloth of the present invention comprises a base cloth, and a coating amount of a water-miscible organic solvent solution having a high viscosity of a polyurethane resin containing a cross-linking agent in a resin solid content of 5 to 15 g / m ² and then a water-miscible organic solvent solution of polyurethane resin having a low viscosity is applied on the coated surface, and then immersed in water to coagulate the polyurethane resin, followed by heating and drying. It is characterized in that the pulling layer and the top pulling layer are simultaneously formed and integrated with the base fabric.

The present invention will be described below with reference to the drawings. As shown in FIG. 1, the moisture-permeable waterproof cloth of the present invention basically comprises a base cloth 1, and an undercoat layer 2 and an uppercoat layer 3 which are laminated on the base cloth 1. Reference numeral 4 in the drawing denotes a skin layer provided as necessary. As the base cloth 1, woven cloth, non-woven cloth, woven cloth and the like can be used, and specifically, woven cloth made of nylon fiber and the like can be mentioned. If necessary, the base cloth 1 may be subjected to a water repellent treatment to impart water repellency.

In the production method of the present invention, first, the base fabric 1 as described above is used, and a water having a high viscosity of a polyurethane resin containing a crosslinking agent for forming an undercoat layer on the base fabric by a flow coater or the like. Apply the miscible organic solvent solution. Then, a low-viscosity water-miscible organic solvent solution of a polyurethane resin for forming an overcoat layer is continuously applied to the application surface by a doctor knife coater or the like. The above-mentioned highly viscous solvent solution has a viscosity at 25 ° C. of 60,000 to
It is 90000 cps, and its basis weight (application amount) is 5 to 15 g / m ² in terms of polyurethane resin solid content. On the other hand, the solvent solution having the above low viscosity has the same viscosity as the above 10
000 to 30,000 cps, and the coating amount is preferably about 30 to 150 g / m ^{2 in the} same conversion. By increasing the viscosity of the solvent solution for forming the undercoat layer,
It is possible to prevent the solvent solution for forming the overcoat layer to be applied thereafter from permeating into the base cloth. Further, since the undercoat layer is a thin film having a smaller film thickness than the overcoat layer, the basis weight is within the above numerical range. If the basis weight is less than 5 g / m ² , the sealing effect is small and the peel strength is insufficient, and if it exceeds 15 g / m ² , the texture becomes hard, which is not preferable for applications such as clothing.

As the above-mentioned polyurethane resin constituting the undercoat layer and the overcoat layer in the present invention, polypropylene glycol type polyurethane, polytetramethylene glycol type polyurethane, polycarbonate type polyurethane, polyester type polyurethane and the like are used.
The 0% modulus is preferably ²⁰ to 100 kg / cm ² . Further, as the water-miscible organic solvent, for example, dimethylformamide (DMF), dimethylacetamide (DMA), tetrahydrofuran (THF), dioxane (DOX), a mixture thereof or the like is used.
The solvent solution of the polyurethane resin may be blended with a cell regulator, a pigment, etc., if necessary.

As the cross-linking agent added to the polyurethane resin for forming the undercoat layer, hexamethylene diisocyanate trimer (HDI) and trimethylolpropane (T
Examples thereof include adducts of MP) and tolylene diisocyanate (TDI), adducts of TMP and HDI, adducts of TMP and isophorone diisocyanate (IPDI), and among them, hexamethylene diisocyanate trimer is preferable. This crosslinking agent has a polyurethane resin solid content of 10
0.1 to 10 parts by weight is added to 0 parts by weight. If the amount of cross-linking agent added is less than this, the undercoat layer and the base fabric (and the overcoat layer)
There is a problem in that the sufficient adhesive strength with and cannot be obtained, and conversely if the amount exceeds the above range, the texture becomes hard. Further, the viscosity adjustment of the solvent solution of the resin, pulp floc, silica,
It is carried out by appropriately adding a thickening (thickening) agent such as calcium carbonate. In the case of pulp floc,
10 to 1 for 100 parts by weight of solid content of polyurethane resin
00 parts by weight is preferred. In particular, when this pulp floc is not added, the water vapor transmission rate (JIS Z 0208) is 10
Although it is about 00g / m ² · 24hr, the moisture vapor transmission rate is 2500g / m when about 10 parts by weight of pulp floc is added.
^The result is more than 2.24 hours and improved.

When the water-repellent treated base cloth 1 is used, the water-repellent treatment is carried out before the coating step. The water repellent treatment can be carried out by a conventionally known treatment method. For example, the base fabric material is dipped in a solution of a water repellent such as fluorine and dried, or the solution of the water repellent is applied to the surface of the base fabric. Apply and perform. By performing this treatment, not only the waterproof performance of the base cloth is obtained, but also the penetration of the coating liquid into the back surface of the base cloth can be prevented in the step of applying the undercoat layer, and the texture of the base cloth can be softened. You can also Conventionally, since the water-repellent base cloth inhibits the adhesion with the resin, the water-repellent treatment is often carried out in the final step, but in the present invention, the adhesive strength between the base cloth and the resin is increased due to the crosslinking by the crosslinking agent. Therefore, there is an advantage that the water-repellent treated base fabric can be used from the beginning to perform the production.

Next, the base cloth 1 which has been subjected to the above-mentioned coating work.
Is immersed in water and then dried by heating. By this water immersion, the solvent is removed to wet-solidify the polyurethane resin, and in the drying step, crosslinking between the resin and the base cloth is performed by the crosslinking agent. As a result, the undercoating layer 2 and the overcoating layer 3 each of which is a microporous layer in which communicating micropores are uniformly present are simultaneously formed, and a moisture-permeable waterproof cloth integrated with the base cloth is obtained. Here, the moisture-permeable waterproof cloth of the present invention is excellent in peel strength between layers due to the presence of the undercoat layer, which means that the crosslinking agent added to the resin for forming the undercoat layer is It is considered that this is an effect obtained by giving priority to the crosslinking reaction between the resins and the base cloth during the drying step rather than the reaction. That is, crosslinking does not easily occur at the substrate temperature (less than 100 ° C) in the presence of water and at the stage of evaporation of water, and the crosslinking reaction proceeds at the substrate temperature during drying (100 ° C or more). Is. This phenomenon is particularly remarkable when hexamethylene diisocyanate trimer is used as a crosslinking agent. By the way, the peel strength when no crosslinking agent is added is (JIS
L 1092) becomes less than 0.6 kg / 3 cm, while the addition of a crosslinking agent as in the present invention results in 1.5 kg / 3 cm.
The above peel strength can be obtained.

Although the moisture permeable waterproof cloth is obtained by the above steps, when the skin layer 4 is further provided on the upper coating layer 3, it may be formed after this. Although desired physical properties can be additionally provided by the skin layer 4, the skin layer needs to be at least a layer having moisture permeability. For example, the undercoat layer and the overcoat layer have a cell structure in which they communicate with each other and have excellent moisture permeability and a very soft texture, but on the other hand, they tend to lack water pressure resistance (water impermeable). A skin layer for can be provided. In that case, it is formed by directly coating a polyurethane resin on the overcoat layer and drying.

The moisture permeable waterproof cloth of the present invention has a moisture permeability (JIS
Z 0208) is 2500 g / m ² · 24 hr or more, water resistance (JIS L 1092 B method) is 2.0 kgf / cm ² or more, water repellency (JIS L 1092) is 90 or more, and base fabric and polyurethane The peel strength between the resin and the wet microporous layer is (JIS L 1092) 1.2 kg /
It is possible to make it 3 cm or more.

[0013]

【Example】

Example 1 A woven fabric of 210 denier nylon ox is dipped in a 10% aqueous solution of Dickguard (manufactured by Dainippon Ink and Chemicals Co., Ltd.), dried and treated for water repellency. An undercoat layer forming solution (viscosity of 70,000 cps) having the following composition was applied to one side of this woven cloth by a flow coater so that the coating amount was 50 g / wt of urethane resin solution.
After coating so as to be m ² , subsequently, a coating layer forming solution (viscosity of 25,000 cps) having the following composition is coated on the coated surface with a doctor knife coater so that the coating amount becomes 200 g / m ^{2 in} terms of the same resin solution weight. To apply. “Part” below
Indicates parts by weight. (Undercoat layer forming solution) -Krisbon MP145 (manufactured by Dainippon Ink and Chemicals, 100 parts, polyurethane with 100% modulus of 45 kg / cm) -Silicon additive 1 part-Polypropylene glycol 2 parts-KC Flock W300 (Sanyo Kokusai Pulp) 20 parts Hexamethylene diisocyanate trimer (manufactured by Dainichiseika) 5 parts Pigment 0.5 parts DMF 40 parts (solution for forming the overcoat layer) Crisbon MP145 100 parts Silicone additive 1 part Polypropylene glycol 2 parts ・ KC Flock W300 10 parts ・ Pigment 0.5 parts ・ DMF 40 parts The woven fabric after application is immersed in water at 25 ° C to remove the solvent to solidify the polyurethane and after dehydration 130 ° C. Dried under hot air. Finally, the resin composition having the following composition is applied with a doctor knife coater so that the coating amount is 50 by weight of the resin solution.
It was applied so as to be g / m ² to form a skin layer and finished to obtain a moisture-permeable waterproof cloth. (Resin composition) -Rezaroid Lu4095 (manufactured by Dainichiseika) 50 parts-Rezaroid Lu4105 mat (manufactured by Dainichiseika) 50 parts-Pigment 20 parts The resulting moisture-permeable waterproof cloth has a moisture vapor transmission rate of 2500 g / m ² .24.
hr, water resistance of 2.0 kgf / cm ² , water repellency of 90 or more,
The texture was also soft. The peel strength between the woven fabric and the upper and lower pulling layers was 1.2 kg / 3 cm. A rain garment was produced using this waterproof cloth, and when it was worn, it was a comfortable material with no stuffiness, no stiffness, and practical durability.

COMPARATIVE EXAMPLE 1 A woven fabric of 210 denier nylon ox is dipped in a 10% aqueous solution of Dickguard (manufactured by Dainippon Ink and Chemicals) and dried to be treated for water repellency. On this base cloth (woven cloth), the same coating solution for forming the overcoat layer as in Example 1 was applied at a solution weight of 20.
It is applied so as to be 0 g / m ² , then immersed in water to remove the solvent to solidify the polyurethane, and after dehydration, the temperature is 130 °.
It was dried under hot air of C, and finally, the same resin composition as in Example 1 was applied to the surface in the same manner to form a skin layer, and a moisture-permeable waterproof cloth was obtained. The moisture-permeable waterproof cloth obtained has a moisture-permeability of 2500 g.
/ M ² · 24 hr, water resistance 2.0 kgf / cm ² , and water repellency 90, but the urethane solution oozes out on the back of the base fabric and the appearance of the base fabric surface is significantly impaired, and the texture is also good. It was hard and the peel strength between the woven cloth and the upper coating layer was 0.4 kg / 3 cm, which was not practical.

[0015]

As described above, the moisture-permeable waterproof cloth of the present invention has a specific weight per unit area (film thickness) of the wet microporous body of the polyurethane resin in which the undercoat layer is crosslinked with the crosslinking agent as described above. Since it is a thin film layer of), due to the balance with the overcoat layer made of the wet-solidified polyurethane resin,
Excellent moisture permeability is obtained. In addition to being waterproof, it has an excellent soft texture. Furthermore, since both the undercoat layer and the overcoat layer are composed of uniform microporous layers, the quality such as moisture permeability is extremely stable. In addition, it has excellent peel strength due to the crosslinking between the resins and the base cloth by the crosslinking agent. Further, according to the production method of the present invention, a production procedure for forming a polyurethane resin layer in which a moisture-permeable waterproof cloth having excellent moisture permeability, waterproofness, texture, and peel strength as described above is subjected to normal wet coagulation and It is possible to easily, quickly, and stably manufacture by a method that is not much different from the operation content.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a moisture-permeable waterproof cloth of the present invention.

[Explanation of symbols]

 1 Base cloth 2 Undercoat layer 3 Overcoat layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B05D 7/24 302 T 8616-4D B32B 5/18 7016-4F 7/02 7188-4F 27/12 7258-4F 27/40 7016-4F 31/24 7141-4F

Claims (2)

[Claims] 1. A moisture-permeable waterproof cloth comprising a base cloth, and an undercoat layer and an undercoat layer made of a wet microporous body of polyurethane resin, which are successively laminated, wherein the undercoat layer is crosslinked with a crosslinking agent. A moisture-permeable waterproof cloth, which is a thin film made of a resin wet microporous material and having a basis weight of 5 to 15 g / m ^{2 in} terms of resin solid content. 2. A high-viscosity water-miscible organic solvent solution of a polyurethane resin containing a cross-linking agent is applied on a base cloth so that the application amount is 5 to 15 g / m ^{2 in} terms of resin solid content. , Furthermore, after applying a water-miscible organic solvent solution having a low viscosity of the polyurethane resin on the coated surface, the polyurethane resin is solidified by immersing it in water and then heat-dried to simultaneously form the undercoat layer and the overcoat layer. A method for producing a moisture-permeable waterproof cloth, which is characterized by being formed and integrated with a base cloth.