KR102293565B1 - Functional polyurethane film excellent in durability and flexibility, and method for manufacturing the same - Google Patents

Abstract

The present invention is a cavity (Cavity); And it relates to a functional polyurethane film containing a plurality of cells and a method for manufacturing the same, including; and a barrier rib including micropores, wherein the plurality of cells and the composite powder remaining after the washing step are included, so it is harmless to the human body In addition, it has excellent moisture permeability and waterproofing effect, durability such as elongation strength, tensile strength, and tear strength is improved, and flexibility is improved. , A bar that lowers the friction coefficient of the surface can protect the skin because it can prevent damage to the skin and increase the moisturizing effect when used as a medical and cosmetic material.
In addition, the manufacturing method of the polyurethane film according to the present invention can simplify the process because there is no need to insert a separate diaphragm film or sheet, and it is economical by reducing the cost, and the amino acid powder used in the manufacturing method is manufactured By improving the speed, the work efficiency can also be increased.

Description

Functional polyurethane film excellent in durability and flexibility, and method for manufacturing the same

The present invention is a cavity (Cavity); and barrier ribs including micropores; to a functional polyurethane film including a plurality of cells and a method for manufacturing the same.

The dry method, one of the methods for manufacturing a polyurethane film, is a method of applying a polar polyurethane solution on a release paper, drying and aging it, and then peeling the film from the release paper. This dry method is the manufacturing process Although this method has the advantage of being relatively simple, it has been subjected to many limitations in its use range due to problems such as lack of surface characteristics, moisture permeability, and loss between volumes peculiar to the dry method.

However, as a wet method capable of solving the various problems has emerged, the wet method is frequently used in a method for manufacturing a polyurethane film in recent years. However, even when the polyurethane film is manufactured through the wet method, when nylon is used as the substrate, there are problems in that it is difficult to control the exudation, the amount of application and the thickness of the film. Therefore, there was a difficulty in that the moisture permeability and elasticity of the prepared film were greatly deteriorated.

In order to solve the problems of the conventional wet method as described above, there were cases in which a polymer filler, fructose or inorganic salt was added to the polyurethane coating composition and then melted to prepare a wet polyurethane sheet including micropores, but even in this case, physical properties There was a problem in that there are many cases of lowering the product, and phthalates, which are harmful to the human body, can remain in the product, which can be harmful to the human body.

Republic of Korea Patent Registration 10-1105184

The present invention is intended to solve the above problems, and the specific objects thereof are as follows.

The present invention is a polyurethane film having excellent durability and flexibility and harmless to the human body, including a pore layer including a plurality of cells (A) including a cavity (a1) and a partition wall (a2) including micropores provides

In addition, the present invention provides a method of manufacturing a polyurethane film that is simplified and competitive compared to the conventional polyurethane film manufacturing process.

The object of the present invention is not limited to the object mentioned above. The objects of the present invention will become more apparent from the following description, and will be realized by means and combinations thereof described in the claims.

The polyurethane film according to an embodiment of the present invention has a cavity (Cavity) (a1); and a porous layer including a plurality of cells (A) including; and a partition wall (a2) including micropores surrounding the cavity.

The polyurethane film is formed on one side of the porous layer, the intermediate layer comprising a polyurethane resin and a crosslinking agent; and a pretreatment layer comprising a water repellent, which is formed on one side and the other side in contact with the porous layer of the intermediate layer.

The partition wall (a2) is a polyurethane resin; and complex powder.

The partition wall (a2) may include 100 parts by weight of a polyurethane resin and 2.5 to 28 parts by weight of the composite powder.

The complex powder may include one selected from the group consisting of water-soluble proteins, fats, and combinations thereof.

The diameter of the cavity (a1) may be 100 to 300 μm, and the size of the micropores may be 0.1 to 5 μm.

The polyurethane film has a thickness of 0.2mm to 2mm, a weight of 100 to 300g/m ² , a tensile strength of 0.5 to 2.0kgf/2.54cm, an elongation of 0.5 to 2.0kgf, and a density of 0.05 to 0.20g/m ³ and hardness (F TYPE) may be 40 to 80 degrees.

The method for manufacturing a polyurethane film according to an embodiment of the present invention comprises the steps of pretreating a substrate to prepare a pretreatment layer, and first coating the pretreatment layer with a primary composite resin composition comprising a polyurethane resin and a crosslinking agent to form an intermediate layer manufacturing a porous layer by secondary coating with a secondary composite resin composition comprising a polyurethane resin and a composite powder on the intermediate layer, and peeling the substrate.

The substrate may include one selected from the group consisting of hydrophilic yarns, hydrophobic yarns, and combinations thereof.

The pretreatment may be performed by treating the substrate with a water repellent at 100 to 160° C. for 1 to 10 minutes.

The water repellent may include one selected from the group consisting of C6 perfluorinated chemical (C6 PFC), C8 perfluorinated chemical (C8 PFC), silicone, and combinations thereof.

The step of preparing the intermediate layer includes a step of first coating the pretreatment layer with a first composite resin composition, a step of coagulation after the first coating, a step of washing with water after solidification, and a step of treating with water for washing, and drying after treatment with water for washing may include steps.

The primary composite resin composition may include 100 parts by weight of a polyurethane resin and 1 to 10 parts by weight of a crosslinking agent.

The first coating may be applied in an amount of 10g to 300g/lm.

The coagulation step may be performed at a temperature of 22 to 28° C. and a dimethylformamide (DMF) aqueous solution of 10 to 15%.

The step of preparing the porous layer is a step of secondary coating the intermediate layer with a secondary composite resin composition, a step of coagulation after the secondary coating, and a washing step of dissolving all or part of the composite powder by treating with water for washing after the solidification. and drying after treatment with the water for washing.

The porous layer may include a plurality of cells A including a cavity a1 and a partition wall a2 including micropores surrounding the cavity.

The secondary composite resin composition may include 100 parts by weight of a polyurethane resin and 5 to 40 parts by weight of the composite powder.

The composite powder may have a size of 0.5 to 5 μm.

The complex powder may include one selected from the group consisting of water-soluble proteins, fats, and combinations thereof.

In the step of peeling the substrate, the peel strength may be 50 to 1000 g/cm.

The polyurethane film according to the present invention includes a partition wall and a cavity including micropores manufactured after the water washing step, and contains the composite powder remaining after the water washing step, so it is not only harmless to the human body, but also moisture permeable and waterproof Excellent effect, improved durability such as elongation strength, tensile strength, and tear strength, and improved flexibility When used as a material for bar medical and cosmetic products, it can protect the skin as it can prevent damage to the skin and increase the moisturizing effect.

In addition, the manufacturing method of the polyurethane film according to the present invention can simplify the process because there is no need to insert a separate diaphragm film or sheet, and it is economical by reducing the cost, and the amino acid powder used in the manufacturing method is manufactured By improving the speed, the work efficiency can also be increased.

The effects of the present invention are not limited to the above-mentioned effects. It should be understood that the effects of the present invention include all effects that can be inferred from the following description.

1 is a cross-sectional view schematically showing a polyurethane film (1) according to the present invention.
2 is a cross-sectional view schematically showing the porous layer 10 included in the polyurethane film (1) according to the present invention.
3A is an image of a cross-section of a polyurethane film prepared by a conventional wet process observed with a scanning electron microscope (SEM).
3b is an image of a cross-section of the polyurethane film prepared according to the present invention observed with a scanning electron microscope (SEM).
4 is a flowchart illustrating a method for manufacturing a polyurethane film according to the present invention.
5 is a flowchart illustrating a method of manufacturing the intermediate layer 20 included in the polyurethane film according to the present invention.
6 is a flowchart illustrating a method of manufacturing the porous layer 10 included in the polyurethane film according to the present invention.

The above objects, other objects, features and advantages of the present invention will be easily understood through the following preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Also, when a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where it is "directly on" another part, but also the case where another part is in the middle. Conversely, when a part of a layer, film, region, plate, etc. is said to be “under” another part, it includes not only cases where it is “directly under” another part, but also cases where another part is in the middle.

Unless otherwise specified, all numbers, values, and/or expressions expressing quantities of ingredients, reaction conditions, polymer compositions and formulations used herein include, among other things, the numbers, values, and/or expressions expressing amounts of ingredients in which such numbers essentially occur in obtaining such values, among others. Since they are approximations reflecting various uncertainties in the measurement, it should be understood as being modified by the term “about” in all cases. Also, where the disclosure discloses numerical ranges, such ranges are continuous and inclusive of all values from the minimum to the maximum inclusive of the range, unless otherwise indicated. Furthermore, when such ranges refer to integers, all integers inclusive from the minimum to the maximum inclusive are included, unless otherwise indicated.

1 is a cross-sectional view schematically showing a polyurethane film (1) according to the present invention. Referring to this, the polyurethane film 1 may include a pore layer 10 including a plurality of cells A including a cavity a1 and a partition wall a2; an intermediate layer 20 comprising a polyurethane resin and a crosslinking agent, which is formed on one side of the layer; and a pretreatment layer 30 including a water repellent, which is formed on one side and the other side in contact with the porous layer of the intermediate layer.

pore layer

2 is a cross-sectional view schematically illustrating the porous layer 10 . Referring to this, the porous layer 10 includes a plurality of cells A including a cavity a1 and a partition wall a2 including micropores surrounding the cavity.

The cavity (a1) included in the cell (A) according to the present invention is not particularly limited as long as it is generated in the polyurethane resin while the composite powder is dissolved through the coagulation/washing process. The diameter of the cavity (a1) according to the present invention may be 100 ~ 300㎛. If the diameter of the cavity (a1) is less than 100 μm, there is a problem in that the moisture absorption function and the sense of volume are reduced, and when it exceeds 300 μm, there is a problem in that the physical properties of the polyurethane film are reduced.

The partition wall (a2) included in the cell (A) according to the present invention may include a polyurethane resin and a composite powder. The polyurethane resin included in the partition wall according to the present invention is not particularly limited as long as it is a polyurethane resin commonly used for producing a polyurethane film, but preferably, polyether polyol, polyester polyol, polycarbonate polyol and their It can be prepared by polymerizing a polyol selected from the group consisting of a combination and an aliphatic or aromatic isocyanate compound commonly used for the production of polyurethane. Even more preferably, the polyol may be a composite polyol in which 40 to 80% by weight of polyether polyol and 20 to 60% by weight of polycarbonate polyol are mixed.

In addition, the complex powder included in the partition wall according to the present invention may include one selected from the group consisting of water-soluble proteins, fats, and combinations thereof. The water-soluble protein according to the present invention may be soybean, corn, sugar, etc. containing amino acids as a type of complex saccharide, and the fat according to the present invention may be vegetable fat, such as vegetable oil, palm oil, palm oil, cacao fat, olive oil, canola oil, It may be sunflower seed oil, grape seed oil, soybean oil, and the like. The water-soluble protein contained in the complex powder according to the present invention may be 6 to 10% by weight and 1.0 to 2.0% of vegetable fat. If the water-soluble protein is less than 6% by weight or the vegetable fat is less than 1.0% by weight, it is difficult to realize a soft touch feeling. If the water-soluble protein exceeds 10% by weight or the vegetable fat exceeds 2.0% by weight, the mechanical properties and There is a disadvantage in that durability is lowered.

The partition wall (a2) included in the cell (A) according to the present invention may include 100 parts by weight of a polyurethane resin and 2.5 to 28 parts by weight of the composite powder. If the compound powder is less than 2.5 parts by weight, it is difficult to implement a soft touch feeling, and if it exceeds 28 parts by weight, the mechanical properties and durability of the product are deteriorated.

The micropores included in the partition wall (a2) according to the present invention are not particularly limited as long as they are generated in the polyurethane resin while the composite powder is dissolved through the solidification/washing process. The size of the micropores according to the present invention may be 0.1-5 μm. If the size of the micropores is less than 0.1 μm, there is a problem in that breathability, hygroscopicity, and spreadability of medical and cosmetic products are reduced, and when it exceeds 5 μm, there is a problem in that mechanical properties (strength) are lowered.

That is, the porous layer according to the present invention, as shown in Figures 3a and 3b, compared to the conventional wet polyurethane resin, a plurality of cavities (a1) and partition walls (a2) including micropores (a2) Because the cell (A) is composed more precisely and densely, and contains composite powder, it has excellent moisture permeability and waterproof effect, durability and flexibility such as tensile, tear and elongation are improved, and the friction coefficient of the surface is lowered. There are features that can be

mezzanine

The intermediate layer 20 according to the present invention is formed on one side of the porous layer, and may include a polyurethane resin and a crosslinking agent, and may further include a diluting solvent and a pigment, and increase the density of the polyurethane film to withstand water pressure. It is not particularly limited as long as it plays a role in increasing the

The polyurethane resin included in the intermediate layer 20 according to the present invention may be the same as or different from the polyurethane resin included in the porous layer.

The crosslinking agent included in the intermediate layer according to the present invention is not particularly limited as long as it can increase the water pressure by increasing the density of the polyurethane film. The crosslinking agent according to the present invention may include, for example, an isocyanate type crosslinking agent, and preferably an isocyanate type crosslinking agent capable of efficiently increasing the density of the polyurethane film of the present invention.

The crosslinking agent according to the present invention has the advantage of being able to control the degree of moisture permeability and water pressure resistance according to the amount contained, and the peel strength can be adjusted according to the amount of application of the intermediate layer when the substrate is peeled off.

pretreatment layer

The pretreatment layer according to the present invention may be formed on one side and the other side in contact with the porous layer of the intermediate layer, and may include a water repellent and water, and a role and base material for balancing the moisture permeability or water pressure of the polyurethane film It is not particularly limited as long as it serves to easily peel off.

The water repellent contained in the pretreatment layer according to the present invention is from the group consisting of C6 perfluorinated chemical (C6 PFC), C8 perfluorinated chemical (C8 PFC), silicone, and combinations thereof. It may include a selected one, and may preferably be a silicone-based water repellent capable of increasing moisture permeability.

The water repellent according to the present invention may be 5 to 35% by weight based on 100% by weight of the total pretreatment layer.

Accordingly, the pretreatment layer included in the polyurethane film according to the present invention may have a thickness of 10 to 100 μm, an application amount of 0.5 to 20 g/lm, and an elastic modulus (modulus) of 30 to 120%. The thickness is less than 10 μm or the application amount is 0.5 g/lm If it is less than, there is a disadvantage that the fabric and the film are separated during wet coating, and when the thickness exceeds 100 μm or the application amount exceeds 20 g/lm, the touch feeling of the polyurethane film becomes hard.

That is, the polyurethane film including the pore layer, the intermediate layer and the pretreatment layer according to the present invention has a thickness of 0.2 mm to 2 mm, a weight of 100 to 300 g/m ² , and a tensile strength of 0.5 to 2.0 kgf/2.54 cm, elongation. Silver 0.5~2.0kgf, density 0.05~0.20g/m ³ , hardness (F TYPE) of 40~80 degrees, compression rate of 90~100%, and recovery rate of 90~100%. It has excellent durability such as , elongation strength, tensile strength, and tear strength, and also has excellent flexibility.

4 is a flowchart showing a method of manufacturing a polyurethane film (1) according to the present invention . Referring to this, the step of preparing a pretreatment layer by pretreatment of the substrate (S10), the first coating with a primary composite resin composition including a polyurethane resin and a crosslinking agent on the pretreatment layer to prepare an intermediate layer (S20), A step of preparing a porous layer by secondary coating on the intermediate layer with a secondary composite resin composition comprising a polyurethane resin and a composite powder (S30) and peeling the substrate included in the pretreatment layer (S40). .

The step of preparing the pretreatment layer (S10) is a step of preparing the pretreatment layer by pretreatment of the base material, that is, the raw material.

The substrate according to the present invention is not particularly limited as long as it can increase the physical strength and moisture permeability, since the physical properties of the polyurethane film, which is the final product, vary depending on the type thereof. The substrate according to the present invention may include one selected from the group consisting of hydrophilic yarns, hydrophobic yarns, and combinations thereof. Preferably, the hydrophilic yarn may include cotton yarn, wool, rayon yarn, nylon yarn, and the like, and the hydrophobic yarn may include polypropylene yarn, polyester yarn, acrylic yarn, and the like, and blended yarns thereof. can The blended yarn according to the present invention may have a ratio of natural fibers to synthetic fibers of 1:99 to 99:1 in order to realize both the characteristics of softness and flexibility of natural fibers and the characteristics of rigidity and hydrophobicity of synthetic fibers. Even more preferably, the substrate according to the present invention may include polypropylene yarn, polyester yarn, acrylic yarn, etc., which are hydrophobic yarns suitable for realizing the pretreatment effect. It is preferable that the thickness of the yarn contained in the base material according to the present invention, that is, the raw base material is 50 to 300 denier. If it is less than 50 denier, there is a fear that physical strength may decrease, and if it exceeds 300 denier, there is a fear that the moisture vapor transmission rate and flexibility may decrease. Accordingly, the substrate including the yarn according to the present invention may have a thickness of 0.5 mm or less and a weight of 120 g/m ² or less, and when the thickness and weight are less than the thickness and weight, the density of the substrate is low to realize the moisture permeability effect, and flexibility and volume are good. good for implementation.

In the pretreatment according to the present invention, it is preferable to perform a water repellent treatment on the substrate according to the present invention, and the water repellent agent for the water repellent treatment is the same as the water repellent agent included in the water repellent layer. Accordingly, the pretreatment according to the present invention may be performed by applying the water repellent to the substrate according to the present invention at 100 to 160° C. for 1 to 10 minutes. If the water-repellent treatment temperature is less than 100 ℃ or the water-repellent treatment time is less than 1 minute, there is a disadvantage that the adhesion strength of the fabric and the water repellent is lowered. Therefore, there is a disadvantage that peeling is difficult.

In the step of preparing the intermediate layer (S20) , the pretreatment layer prepared by the method of S10 is first coated with a first composite resin composition including a polyurethane resin and a crosslinking agent, and then coagulated, washed with water and dried. This is a step to prepare an intermediate layer. 5 is a flowchart illustrating a method for manufacturing an intermediate layer according to the present invention. Referring to this, the step of first coating the pretreatment layer with the first composite resin composition (S21), the step of coagulating after the first coating (S22), the step of washing with water after coagulation (S23) and the washing with water It may include a step of drying after treatment with water (S24).

The first coating step (S21) is a step of coating the first composite resin composition including a polyurethane resin and a crosslinking agent on the pretreatment layer. The polyurethane resin and crosslinking agent included in the primary composite resin composition according to the present invention may be the same as or different from the polyurethane resin and crosslinking agent included in the intermediate layer according to the present invention. In addition, the primary composite resin composition according to the present invention may further include a diluting solvent and a pigment. The polyurethane resin and the crosslinking agent included in the primary composite resin composition according to the present invention may include 100 parts by weight of the polyurethane resin and 1 to 10 parts by weight of the crosslinking agent. When the crosslinking agent is less than 1 part by weight, there is a disadvantage in that the physical properties of the product are lowered, and when it exceeds 10 parts by weight, the flexibility is lowered and the touch feeling of the product is hard. In addition, the diluent solvent may be selected from the group consisting of, for example, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, ethyl acetate, and combinations thereof, and the pigment may be, for example, of various colors. As a pigment (Pigment), the vehicle may include a polyurethane resin (PU RESIN), and each may be 10 parts by weight based on 100 parts by weight of the polyurethane resin. The primary coating for coating the primary composite resin composition according to the present invention on the pretreatment layer may be coated with a uniform thickness over the entire fabric of the substrate on a continuously moving substrate, for example, a floating knife (floating knife) ), a slot die coater, a comma coater, a knife coater, etc., but preferably a floating knife capable of coating with a uniform thickness on a moving substrate. The amount of application of the first composite resin composition applied to the pretreatment layer with a floating knife according to the present invention may be 10 to 300 g/lm. If the application amount is less than 10 g/lm, defects may occur in the coating process and the fabric and the polyurethane (PU) layer may be separated.

The solidifying step (S22) is a step of solidifying the primary composite resin composition coated on the pretreated substrate while passing it through 10 to 15% of an aqueous solution of dimethylformamide (DMF) at a temperature of 22 to 28 ° C. If the solidification temperature condition is less than 22 ℃, the size of the cell is large, there is a disadvantage that the durability of the product is lowered, and if it exceeds 28 ℃, solidification does not occur, and defective products may be manufactured. In addition, if the concentration of the DMF aqueous solution is less than 10%, it may not solidify, resulting in defective products, and if it exceeds 15%, cell non-uniformity may occur.

The washing step (S23) is a step of coagulating the primary composite resin composition coated on the pre-treated substrate and then treating it with water for washing. The washing water used in the washing step according to the present invention may be general industrial water or groundwater.

The drying step (S24) is a step of preparing an intermediate layer by drying the primary composite resin composition, which is coated on the pretreated substrate, and then treated with coagulation and washing water.

The step of preparing the porous layer (S30) is a secondary composite resin composition comprising a polyurethane resin and a composite powder on one side and the other side in contact with the pretreatment layer of the intermediate layer prepared by the manufacturing method of S20. After car coating, it is a step of preparing a porous layer through coagulation, water washing and drying steps. 6 is a flowchart illustrating a method for manufacturing a porous layer according to the present invention. Referring to this, the second coating of the intermediate layer with the secondary composite resin composition (S31), the step of solidifying after the secondary coating (S32), and treatment with water for washing after solidification to dissolve all or part of the composite powder It may include a step of washing with water (S33) and a step of drying after treatment with the water for washing (S34).

The secondary coating step (S31) is a step of coating the intermediate layer (one side in contact with the pretreatment layer and the other side) with a secondary composite resin composition comprising a polyurethane resin and a composite powder. The polyurethane resin and composite powder included in the secondary composite resin composition according to the present invention may be the same as or different from the polyurethane resin and composite powder included in the porous layer according to the present invention. The secondary composite resin composition according to the present invention may include 100 parts by weight of a polyurethane resin and 5 to 40 parts by weight of the composite powder. If the weight part of the composite powder is less than 5 parts by weight, the moisture permeability effect may be reduced due to the small amount of cavities formed through the water washing step later, and if it exceeds 40 parts by weight, there is a risk that the film formability may be deteriorated and the surface strength may be lowered. can In addition, the size of the composite powder included in the secondary composite resin composition according to the present invention may be 0.5-5 μm. In addition, the composite powder according to the present invention has a feature that can improve the coagulation rate by helping the penetration of the DMF aqueous solution in the coagulation tank during coagulation later, thereby increasing the efficiency of work. The secondary coating of coating the secondary composite resin composition according to the present invention on the intermediate layer may be the same as or different from the primary coating method included in the step of preparing the intermediate layer. The application amount of the secondary composite resin composition applied to the intermediate layer may be 3000 ~ 4000 g / lm. If the application amount is less than 3000g/lm, the product thickness becomes thin and spreadability is poor when used as a cosmetic liquid or other cosmetic applicator. has the disadvantage of falling.

The solidifying step (S32) is a step of solidifying the secondary composite resin composition coated on the intermediate layer while passing it through 2 to 10% of an aqueous solution of DMF at a temperature of 30 to 50°C. If the coagulation temperature condition is less than 30℃, the dissolution of the added protein becomes slow and the cells become non-uniform. There are possible drawbacks. In addition, when the concentration of the DMF aqueous solution is less than 2%, the cells are irregular and the spreadability of the cosmetic solution is reduced, and when it exceeds 10%, the cells are small and the cushion feeling is reduced. Accordingly, a feature of the present invention is that by controlling the temperature and concentration conditions of the aqueous solution, it is possible to control the size, density and precision of the cell including the cavity and the partition wall, which is manufactured through a subsequent washing step.

The washing step (S23) is a step of treating the secondary composite resin composition coated on the intermediate layer with water for washing after coagulation. The washing water used in the washing step according to the present invention may be general industrial water or groundwater. Accordingly, the composite powder according to the present invention included in the secondary composite resin composition is included in the polyurethane resin in the solidification step, and is dissolved and removed through the water washing step. cells can be created. At this time, the cavities included in the formed cells and the micropores included in the partition walls are uniform and have characteristics that do not degrade the mechanical/chemical properties of the product. In addition, even if washed with water, the composite powder contained in the polyurethane resin is harmless to the human body and does not irritate the human body, so it can be used in the medical and cosmetic fields.

The drying step (S34) is a step of finally preparing a porous layer by drying the secondary composite resin composition that is coated on the intermediate layer and then treated with coagulation and washing water. Drying according to the present invention may dry the secondary composite resin composition treated with the washing water at a chamber temperature of 100 ~ 130 ℃. If the drying chamber temperature is less than 100 ℃, it takes a long time to dry and the economic feasibility of the product is lowered.

The peeling step (S40) is a step of peeling the substrate located on the pretreatment layer. The peeling step according to the present invention may have a peel strength of 50 to 1000 g/cm. If the peel strength is less than 50 g/cm, the substrate may be peeled off during the polyurethane film manufacturing process, and if it exceeds 1000 g/cm, the polyurethane film may be peeled off in the peeling process.

The present invention will be described in more detail with reference to the following examples. The following examples are merely examples to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example 1-1

(S10) A substrate having a ^{thickness of 0.2 mm and a weight of 110 g/m 2} including a polyester yarn having a thickness of 20 denier as a hydrophobic yarn was prepared. Then, a water repellent treatment was performed for 1 minute at 130° C. with a water repellent containing 30 wt% of JF-08310F, a silicone water repellent, on the prepared substrate to prepare a pretreatment layer. At this time, the thickness of the pretreatment layer was 0.1 μm or less, and the application amount was 150 g/lm.

(S20) A primary composite resin composition was prepared and coated on the pretreatment layer prepared according to the above method. Specifically, 100 parts by weight of a polyurethane resin prepared by polymerizing 80 g of a composite polyol mixed with 60% by weight of polyether polyol and 40% by weight of polycarbonate polyol and 20 g of an isocyanate compound; 3 parts by weight of CLA-300, an isocyanate-type crosslinking agent; 10 parts by weight of DMF as a diluent; And a primary composite resin composition comprising 10 parts by weight of a toner as a pigment was prepared. Then, the prepared primary composite resin composition was applied to the pretreatment layer continuously moving with a floating knife, a coating technique, at an application amount of 22 g/lm and coated.

The first composite resin composition coated on the pretreatment layer was coagulated while passing through 13% of an aqueous solution of dimethylformamide (DMF) at a temperature of 35°C.

After the primary composite resin composition coated on the pre-treated substrate was solidified, it was washed with water at a temperature of 35° C. for 5 minutes.

Then, after being coated on the pre-treated substrate, the first composite resin composition treated with coagulation and washing water was dried at a chamber temperature of 130° C. to prepare an intermediate layer on the pre-treatment layer.

(S30) A secondary composite resin composition was prepared and coated on the prepared intermediate layer (on one side and the other side in contact with the pretreatment layer). Specifically, 100 parts by weight of a polyurethane resin prepared by polymerizing 80 g of a composite polyol mixed with 40% by weight of polyether polyol and 60% by weight of polycarbonate polyol and 20 g of an isocyanate compound; And 99.5% by weight of water-soluble protein and 0.5% by weight of vegetable fat to prepare a secondary composite resin composition comprising 10 parts by weight of the complex powder. Then, the prepared secondary composite resin composition was applied at an application amount of 3500 g/lm to the intermediate layer continuously moving with a floating knife, which is a coating technology, and coated.

The first composite resin composition coated on the intermediate layer was coagulated while passing through 5% of an aqueous solution of dimethylformamide (DMF) at a temperature of 35°C.

After coagulating the secondary composite resin composition coated on the intermediate layer, it was washed with water at a temperature of 60° C. for 150 minutes.

Then, the secondary composite resin composition coated on the pre-treated substrate, coagulated and treated with water for washing was dried at a chamber temperature of 100° C. to prepare a porous layer on the intermediate layer.

(S40) After buffing the base material including the pretreatment layer, the intermediate layer and the pore layer in a buffing roller, the base material positioned on the pretreatment layer was peeled with a peel strength of 100 g/cm to prepare a polyurethane film. Thereafter, the peeled and wound polyurethane film was dried with 30% of a silicone-based softener at 90° C. and then treated.

Example 1-2

Compared with Example 1-1, a polyurethane film was prepared in the same manner as in Example 1-1, except that a pretreatment layer was prepared by using 16 to 25% by weight of a silicone-based water repellent instead of 30% by weight.

Examples 1-3

Compared with Example 1-1, a polyurethane film was prepared in the same manner as in Example 1-1, except that the pretreatment layer was prepared by using 5 to 15% by weight of the silicone-based water repellent instead of 30% by weight.

Example 2-1

Polyurethane in the same manner as in Example 1-1, except that the intermediate layer was prepared by using 1-2 parts by weight instead of 3-4 parts by weight of the crosslinking agent used for preparing the intermediate layer as compared with Example 1-1. A film was prepared.

Example 2-2

Polyurethane in the same manner as in Example 1-1, except that the intermediate layer was prepared using 5 to 6 parts by weight instead of 3 to 4 parts by weight of the crosslinking agent used for preparing the intermediate layer as compared with Example 1-1. A film was prepared.

Example 2-3

Polyurethane in the same manner as in Example 1-1, except that the intermediate layer was prepared by using 7 to 8 parts by weight instead of 3 to 4 parts by weight of the crosslinking agent used for preparing the intermediate layer as compared with Example 1-1. A film was prepared.

Example 2-4

Polyurethane in the same manner as in Example 1-1, except that the intermediate layer was prepared by using 9 to 10 parts by weight instead of 3 to 4 parts by weight of the crosslinking agent used for preparing the intermediate layer as compared with Example 1-1. A film was prepared.

Comparative Example 1-1

Compared with Example 1-1, Example 1 except that the water repellent used in the preparation of the pretreatment layer was used as a C6 perfluorinated chemical (C6 PFC) instead of the silicone water repellent to prepare the pretreatment layer. A polyurethane film was prepared in the same manner as in -1.

Comparative Example 1-2

Compared with Example 1-1, the water repellent used in preparing the pretreatment layer was 16 to 25 wt% of C6 perfluorinated chemical (C6 PFC) instead of the silicone water repellent, except for preparing the pretreatment layer and a polyurethane film was prepared in the same manner as in Example 1-1.

Comparative Example 1-3

Compared with Example 1-1, the water repellent used in the preparation of the pretreatment layer was 5 to 15% by weight of C6 perfluorinated chemical (C6 PFC) instead of the silicone water repellent, except for preparing the pretreatment layer and a polyurethane film was prepared in the same manner as in Example 1-1.

Comparative Example 2-1

Compared with Example 1-1, Example 1 except that the water repellent used in the preparation of the pretreatment layer was used as a C8 perfluorinated chemical (C8 PFC) instead of a silicone water repellent to prepare the pretreatment layer. A polyurethane film was prepared in the same manner as in -1.

Comparative Example 2-2

Compared with Example 1-1, the water repellent used in preparing the pretreatment layer was 16 to 25 wt% of C8 perfluorinated chemical (C8 PFC) instead of the silicone water repellent, except for preparing the pretreatment layer and a polyurethane film was prepared in the same manner as in Example 1-1.

Comparative Example 2-3

Compared with Example 1-1, the water repellent used in the preparation of the pretreatment layer was 5 to 15% by weight of C8 perfluorinated chemical (C8 PFC) instead of the silicone water repellent, except for preparing the pretreatment layer and a polyurethane film was prepared in the same manner as in Example 1-1.

Comparative Example 3

Polyurethane in the same manner as in Example 1-1, except that the intermediate layer was prepared by using 7 to 8 parts by weight instead of 3 to 4 parts by weight of the crosslinking agent used for preparing the intermediate layer as compared with Example 1-1. A film was prepared.

Experimental Example 1 - Comparison of moisture permeability and water pressure resistance according to the type and content of the water repellent used for pretreatment

The moisture permeability and water pressure resistance of the polyurethane film prepared according to Examples 1-1 to 1-3 and the polyurethane film prepared according to Comparative Examples 1-1 to 2-3 were compared.

Specific results are shown in Table 1 below.

water repellent weight(%) Water vapor permeability (g/m ² *24Hr) Water pressure (mmH20) line
city
Yes 1-1 silicone 26-35 5,999 5,967 1-2 16-25 6,074 5,835 1-3 5-15 6,488 5,623 rain
school
Yes 1-1 C6 PFC system 26-35 5,622 8,952 1-2 16-25 5,869 7,255 1-3 5-15 5,978 6,952 rain
school
Yes 2-1 AC8 PFC system 26-35 5,686 9,855 2-2 16-25 5,753 9,235 2-3 5-15 5,875 8,541

*Measurement method for moisture permeability (KS K 0594): Fill the test cup with the middle blow method, turn the fabric upside down, and measure the amount of moisture permeating through the fabric. Specifically, put 42 mL of water at about 40°C into a moisture-permeable cup preheated to 40°C, and adjust the distance between the water and the test piece to be 10mm. After that, three 70 mm test pieces are taken and fixed with the back side facing water. After that, place it in a constant temperature and humidity device in which air with a temperature of 38 to 42 ° C and a relative humidity of 45 to 55% circulates, and after 1 h, take out the specimen and measure the mass a1. Measure a2 to 1 mg. By substituting the measured result value into the following formula, the moisture permeability is calculated. The average value measured three times is expressed as an integer digit in g/m2/h. [Equation 1]

- P = moisture permeability (g/(m ² h)

-a2-a1 : Change in mass of the specimen after 1 h (g/h)

-S : Breathable area (m ² )

*Water resistance measurement method (KS K ISO 811): This is a method of measuring the water pressure at the moment when three water droplets start to form on the surface of the fabric as the water pressure of the fabric after applying water pressure. Specifically, record _{the pressure in cmH 2} O when water starts to appear in three places from the specimen. At this time, refer to KS K ISO 811 for the accuracy of recording pressure and determination of effective values, but test it arbitrarily on a test piece so that at least 5 valid values can be taken.

As shown in Table 1, when the pretreatment layer was prepared using a silicone-based water repellent, the moisture permeability was relatively higher than when the pretreatment layer was prepared using the C6 and C8 perfluorinated compound-based water repellents of Comparative Examples 1 and 2 series. higher could be seen.

Therefore, the present invention is characterized by excellent moisture permeability and waterproof effect. However, when a silicone-based water repellent is used, the water resistance is relatively lower than when a perfluorinated compound-based water repellent is used. Therefore, the process can be simplified and economical efficiency can be increased.

Experimental Example 2 - Comparison of water pressure resistance according to the amount of crosslinking agent added to the intermediate layer

The moisture permeability and water pressure resistance of the polyurethane film prepared according to Example 1-1 and Examples 2-1 to 2-3 and the polyurethane film prepared according to Comparative Example 3 were compared.

Specific results are shown in Table 2 below.

comparative example
and
Example part by weight of crosslinking agent Water vapor permeability (g/m ² *24Hr) Water pressure (mmH20) Comparative Example 3 - 5,950 8,652 Example 2-1 1-2 5,705 9,150 Example 1-1 3-4 5,626 10,250 Example 2-2 5-6 5,568 10,580 Example 2-3 7-8 4,658 10,780 Example 2-4 9-10 4,159 10,855

*Measuring method for moisture permeability (KS K 0594): Same as above Table 1 method *Measuring method for water pressure resistance (KS K ISO 811): Same as above Table 1 method

As shown in Table 2, as the weight of the crosslinking agent increases with respect to 100 parts by weight of the polyurethane resin in the primary composite resin composition, the density of the polyurethane is increased in the coagulation/washing step, the moisture permeability is lowered, but the water resistance is gradually increasing. could confirm that Therefore, the present invention is characterized in that it is possible to manufacture a polyurethane film that satisfies the target values of moisture permeability and water pressure resistance through control of the weight part of the crosslinking agent.

In the present invention, a polyurethane film was prepared by using a primary composite resin composition containing 3 to 4 parts by weight of a crosslinking agent having both moderately high moisture permeability and water resistance. Accordingly, the polyurethane film prepared according to the present invention has excellent moisture permeability and waterproof effect, and not only has improved durability such as elongation strength, tensile strength, and tear strength, but also includes an intermediate layer containing the crosslinking agent. Since there is no need to insert a diaphragm film or sheet of

1: polyurethane film
10: pore layer 20: intermediate layer 30: pretreatment layer
A: cell a1: cavity a2: septum

Claims (21)

Cavity (a1) and
a porous layer including a plurality of cells (A) including a partition wall (a2) including micropores surrounding the cavity;
an intermediate layer comprising a polyurethane resin and a crosslinking agent, which is formed on one side of the porous layer; and
A pretreatment layer comprising a water repellent, which is formed on one side and the other side in contact with the porous layer of the intermediate layer;
The water repellent is a polyurethane film comprising a silicone-based water repellent. delete According to claim 1,
The partition wall (a2) is a polyurethane resin; and
A polyurethane film comprising a composite powder. 4. The method of claim 3,
The partition wall (a2) is a polyurethane film comprising 100 parts by weight of a polyurethane resin and 2.5 to 28 parts by weight of a composite powder. 4. The method of claim 3,
The composite powder is a polyurethane film comprising one selected from the group consisting of water-soluble proteins, fats, and combinations thereof. According to claim 1,
The diameter of the cavity (a1) is 100-300 μm, the size of the micropores is a polyurethane film of 0.1-5 μm. According to claim 1,
Thickness is 0.2mm ~ 2mm, weight 100 ~ 300g / m ^2, a tensile strength of 0.5 ~ 2.0kgf / 2.54cm, elongation 0.5 ~ 2.0kgf, density of 0.05 ~ 0.20g / m ^3, hardness (F TYPE) is A polyurethane film of 40 to 80 degrees, a compression rate of 90 to 100%, and a recovery rate of 90 to 100%. Pre-treating the substrate with a water repellent to prepare a pre-treatment layer;
preparing an intermediate layer by first coating the first composite resin composition including a polyurethane resin and a crosslinking agent on the pretreatment layer;
preparing a porous layer by secondary coating on the intermediate layer with a secondary composite resin composition comprising a polyurethane resin and a composite powder; and
peeling the substrate;
The water repellent is a method for producing a polyurethane film comprising a silicone-based water repellent. 9. The method of claim 8,
The substrate is a method for producing a polyurethane film comprising one selected from the group consisting of hydrophilic yarns, hydrophobic yarns, and combinations thereof. 9. The method of claim 8,
The pre-treatment is a method for producing a polyurethane film by treating the water repellent on the substrate for 1 to 10 minutes at 100 to 160 ℃ conditions. delete 9. The method of claim 8,
The step of preparing the intermediate layer is
first coating the pretreatment layer with a first composite resin composition;
coagulating after the first coating;
a water washing step of treating with water for washing after the coagulation; and
Method for producing a polyurethane film comprising the step of drying after treatment with the water for washing. 9. The method of claim 8,
The primary composite resin composition is a method of manufacturing a polyurethane film comprising 100 parts by weight of a polyurethane resin and 1 to 10 parts by weight of a crosslinking agent. 13. The method of claim 12,
The primary coating is a method for producing a polyurethane film in an application amount of 10g ~ 300g / lm. 13. The method of claim 12,
The coagulation step is a method of manufacturing a polyurethane film to be solidified at a temperature of 22 ~ 28 ℃ and dimethylformamide (Dimethylformamide; DMF) aqueous solution 10 ~ 15% conditions. 9. The method of claim 8,
The step of preparing the porous layer is
secondary coating of the intermediate layer with a secondary composite resin composition;
coagulating after the secondary coating;
a water washing step of dissolving all or part of the complex powder by treating with water for washing after the coagulation; and
Method for producing a polyurethane film comprising the step of drying after treatment with the water for washing. 17. The method of claim 16,
The porous layer is a cavity (Cavity) (a1) and
Surrounding the cavity, the method for producing a polyurethane film comprising a plurality of cells (A) including a partition wall (a2) including micropores. 9. The method of claim 8,
The secondary composite resin composition is a method of producing a polyurethane film comprising 100 parts by weight of a polyurethane resin and 5 to 40 parts by weight of the composite powder. 9. The method of claim 8,
The composite powder is a method for producing a polyurethane film having a size of 0.5 to 5 μm. 18. The method of claim 17,
The composite powder is a method for producing a polyurethane film comprising one selected from the group consisting of water-soluble proteins, fats, and combinations thereof. 9. The method of claim 8,
The step of peeling the substrate is a method for producing a polyurethane film having a peel strength of 50 ~ 1000 g / cm.

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