Method for manufacturing a resin net for Katsura tree bases and a resin net for Katsura tree bases

Abstract

To provide a technology that reduces waste generation and environmental problems by simplifying the process and avoiding complicated procedures, and that produces a resin net for Katsura wood that has excellent breathability and good heat resistance and chemical resistance. [Solution] A resin net for the base of a wig, and a method for producing it, wherein the net-like fabric is made by impregnating a filament material constituting a net-like fabric with a urethane resin or urea resin, and the impregnated urethane resin or urea resin is impregnated with a low molecular weight compound consisting of a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less and a low molecular weight polyisocyanate component with a molecular weight of 250 or less in which the isocyanate functional group is sealed with a blocking agent, and the net-like fabric is made by pressing the net-like fabric onto a mold shaped like a head and generating a reaction product of urethane bonds or urea bonds by heat.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a resin net for a wig base and a resin net for a wig base that can be used for a wig covering a bald or hair-loss area on the head.

Background Art

[0002] Generally, a wig is composed of human hair or artificial hair (hereinafter, human hair and artificial hair are abbreviated as "hair") planted on a resin net for a wig base (hereinafter, also referred to as a "wig base" or simply "net"). When planting hair on a wig base, in order to make it look as if hair is growing from the scalp, V-shaped hair implantation that only allows hair to be inserted through the wig base is often used. In the case of V-shaped hair implantation, since the hair is simply implanted in a V shape, it can be easily pulled out by brushing or the like. Therefore, after hair implantation, the hair is fixed and held by applying an adhesive diluted with a solvent from the back surface of the wig base and solidifying it. This method is extremely easy in the manufacturing process, but since it is easy to form a film of the adhesive on the back surface, there is a problem in the air permeability of the manufactured wig.

[0003] When emphasizing air permeability, a method of fixing and holding the hair by tying the hair after V-shaped hair implantation on a wig base with good air permeability can be considered. According to this method, the shape can be maintained while maintaining air permeability, but there is a problem that the manufacturing process of the wig is complicated and extremely difficult.

[0004] Regardless of the conventional method used to manufacture the wig described above, a resin net (net) molded into the desired shape is first required for the base. Patent documents 1 and 2 describe methods for manufacturing the net. Specifically, a thin film of synthetic resin for release is applied to a male mold of the head shape, which has been previously molded from the user's head. Next, a first net for absorbing the immersion resin is placed on top of the film, and then the second net, which is the final target, is applied. Next, a resin liquid for coating is applied to the mold in the laminated state, or the mold in the laminated state is immersed in the coating liquid. After drying, the thin film and the first net are separated to produce the desired second net. The thin film described above is for releasing the first net from the male mold and is discarded after the process is completed, so inexpensive materials such as polyethylene are used. The first net described above is also discarded after the process is completed, as its purpose is to absorb the coating liquid and prevent a resin film from forming on the mesh of the second net. Therefore, the first net is made of an inexpensive material, such as nylon stockings. In contrast, the second net, which forms the base of the wig, is made of a woven fabric such as nylon filament.

[0005] In the conventional net manufacturing method described above, the female mold used to create the male mold from the user's head is made of a sheet that is extremely hard at room temperature, but softens at a relatively low temperature so as not to cause the user discomfort from the temperature during molding. For example, Patent Document 3 discloses the use of trans-type polyisolene, which softens at a temperature higher than room temperature and hardens when cooled to room temperature. Other materials such as polycaprolactone sheets are also used. Furthermore, Patent Document 3 describes how these resins can withstand the heat generated when gypsum hardens, and how a male mold using gypsum can be made by coating the inner surface of the female mold with a thin layer of a gypsum and water mixture. When this method is used, the gypsum hardens and can be released, resulting in a male mold that replicates the shape of the user's head. Then, the net is manufactured using this gypsum male mold in the procedure described above.

[0006] In recent years, devices have been disclosed and are being used that acquire three-dimensional shape information from the user's head without using a mold sheet, replacing the previous method of creating male molds by pressing a sheet onto the user's head (see Patent Document 4 or Patent Document 5, etc.). This method involves covering the user's head with a sheet printed with multiple characters and creating a three-dimensional model of the head based on images of the head taken in that state. With the development of such a method, the process of pressing a sheet onto the user's head for molding is eliminated, thus reducing the burden on wig wearers, such as the feeling of pressure during wig production. The above-mentioned patent documents do not describe the process of creating a net based on the information of the obtained three-dimensional model, but generally, it is conceivable to create a resin head shape using a 3D printer based on this information. Then, it is conceivable to create a net (wig base) by applying the manufacturing process described in Patent Documents 1 and 2, which were described earlier, to the obtained resin head. However, even when creating a net by applying the process described in the prior art to the resin head obtained as described above, it is difficult due to the effects of heat and solvents, as explained earlier. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 3-69601 [Patent Document 2] Japanese Patent Publication No. 124615 / 1983 [Patent Document 3] Japanese Patent Application Publication No. 58-54012 [Patent Document 4] Patent No. 7333196 [Patent Document 5] Japanese Patent Publication No. 2024-67555 [Overview of the project] [Problems that the invention aims to solve]

[0008] Alternatively, one could wrap multiple layers of thin film around the user's head to create a mold, then create a plaster mold from this mold, and use the resulting mold to obtain the net using the conventional procedure described earlier. In this case, there is the advantage that relatively inexpensive vinyl resin can be used as the film for molding, but there is another problem: a lack of precision in molding.

[0009] Furthermore, although the procedure for creating a plaster mold from the user's head differs from conventional methods, the net manufacturing process is the same as in the conventional technology. That is, basically, multiple coverings are covered onto the mold, a coating liquid is applied or immersed, and after a heat drying process, the net is separated from the coverings to produce the desired net. For this reason, as explained earlier, the net manufacturing process is complicated, and the resulting net tends to lack breathability.

[0010] According to the inventors' studies, in addition to the problems mentioned above, the conventional net manufacturing process had the following problems. In the conventional method, a thin film, a first net for immersion resin absorption, and a second net are laminated onto the head of a male mold. After coating with resin liquid or immersing in resin liquid and drying the coating liquid, the second net, which will be the final product, is separated to produce the net product. At that time, as described in the aforementioned conventional method (Patent Document 1), the intersection points of the nylon filament mesh of the second net are welded with an ultrasonic welder or the like as needed. As described above, the conventional method has problems that need to be solved in terms of manufacturing efficiency, such as the implementation of multiple complicated procedures and the need for materials that will ultimately be discarded, as well as in terms of effective use of resources.

[0011] Furthermore, there are also environmental and safety issues that need to be addressed, as listed below. As described in Patent Documents 1 and 2 mentioned earlier, polyurethane elastomers are generally used in conventional coating solutions due to their strength and elasticity. The solvents used in these elastomers are polar solvents such as methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), and toluene, which pose environmental and safety challenges due to the generation of malodorous odors and harmful gases during the drying process. Therefore, it is desirable to reduce the amount of solvents used as much as possible. As stated above, there is a need to overcome various technical challenges that arise in the manufacturing process of resin nets for Katsura tree bases.

[0012] Furthermore, the resin net used as the base for wigs is used to create the wig product by implanting hair into it. However, wigs are repeatedly washed with water or hot water using shampoo, etc., and styled using a variety of hair products and hair dryers. Therefore, the resin net used as the base for wigs must have good heat resistance, chemical resistance, and excellent durability. In addition, when using a wig, the issue of breathability is a serious concern for the wearer, and there is a need for the development of a resin net for wig bases that can achieve good breathability when used as a wig.

[0013] Therefore, the object of the present invention is to provide a means for manufacturing resin nets for Katsura tree bases and to solve various technical problems that arise in Katsura trees after manufacturing. Specifically, the object is to provide a technology that simplifies the conventionally complex procedure, enabling the production of resin nets for Katsura tree bases in a simple method with fewer steps and without requiring complicated procedures, minimizing waste generation, reducing environmental problems such as the generation of harmful gases during the drying process, and providing a Katsura tree base resin net that exhibits excellent breathability, good heat resistance, and chemical resistance. [Means for solving the problem]

[0014] The above objectives are achieved by the method for manufacturing a resin net for Katsura tree bases and the Katsura tree base resin net of the present invention. The present invention provides the following method for manufacturing a resin net for Katsura tree bases. [1] A method for manufacturing a resin net for the base of a wisteria tree, which is made of a net-like woven fabric having shape-retaining properties, An impregnation step in which a low molecular weight compound is impregnated into the filament material constituting the net-like fabric with a mixture of a low molecular weight compound comprising a polyol component or polyamine component with a molecular weight of 250 or less, which does not react at room temperature and can generate urethane bonds or urea bonds when heated, and a low molecular weight polyisocyanate component with a molecular weight of 250 or less, in which the isocyanate functional group is encapsulated with a blocking agent. A method for manufacturing a resin net for a wig base, characterized by comprising a step of generating urethane bonds or urea bonds to impart shape retention to the fabric, wherein the fabric, in which the filament material has been impregnated with the low molecular weight compound in the impregnation step, is heated while being pressed onto a mold shaped like a head, and the heating generates urethane bonds or urea bonds to polymerize the fabric.

[0015] The following are preferred embodiments of the above-mentioned method for manufacturing resin netting for Katsura plateaus. [2] The method for producing a resin net for Katsura plateaus according to [1] above, wherein the low molecular weight compound comprises a polyol component and / or polyamine component having two or more alcohol and / or amine functional groups and a molecular weight of 250 or less, and a polyisocyanate component having three or more isocyanate functional groups, having an isocyanate content of 17% or more and 25% or less in the molecule and a molecular weight of 250 or less, and wherein the isocyanate functional groups are sealed with a blocking agent. [3] A method for manufacturing a resin net for a wisteria base according to [1] or [2] above, wherein the filament material constituting the fabric is made of nylon and / or polyester. [4] The method for manufacturing a resin net for a Katsura tree base according to any one of [1] to [3] above, wherein the shape retention is confirmed by wrapping the fabric, which has been impregnated with the low molecular weight compound consisting of the mixed solution for 3 minutes, in strips of 5 cm width and 20 cm length or longer, around the outer circumference of an annular aluminum rod having a thickness of 2 mm and a cross-sectional shape of a square with sides of 5 cm, and cutting off the excess portion that extends beyond the outer circumference of the rod, and then placing the rod with the fabric wrapped around it into a heating furnace and heating at 180°C for 10 minutes to generate urethane bonds or urea bonds, and then removing the sample for shape retention evaluation from the heating furnace and returning it to room temperature, releasing the fabric from the rod, grasping one end of the released 5 cm × 5 cm × 5 cm cubic shaped fabric and letting it hang naturally, measuring the angle of the corner formed on the released fabric by the rod, and confirming that the measured angle is within the range of 90 degrees to 95 degrees, with the 90 degrees of the rod as the reference.

[0016] As another embodiment of the present invention, the present invention provides the following resin net-1 for Katsura tree bedrock. [5] A resin net for the base of a Katsura tree obtained by the method for manufacturing a resin net for the base of a Katsura tree described in any one of [1] to [4] above, A resin net for Katsura trees, characterized in that the filament material constituting the net-like fabric is polymerized by the formation of urethane bonds or urea bonds, and the state of formation of the urethane bonds or urea bonds is configured such that the presence rate of film formation in the mesh of the net-like fabric is low, thereby giving the net-like fabric shape retention properties.

[0017] As another embodiment of the present invention, the present invention provides the following resin net-2 for Katsura tree bedrock. [6] A resin net for the base of a Katsura tree, formed from a net-like woven fabric having shape-retaining properties, The net-shaped fabric is impregnated with a urethane resin or an urea resin, and the impregnated urethane resin or urea resin does not react at room temperature and can form a urethane bond or an urea bond by heating. It is composed of a mixture of a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less and a low molecular weight polyisocyanate component with a molecular weight of 250 or less in which the isocyanate functional group is blocked by a blocking agent. The net-shaped fabric impregnated with a low molecular compound is characterized in that it is a reactant of a urethane bond or an urea bond generated by heat in a state where it is pressed against a mold with the head shaped.

[0018] Preferred forms of the above wig base resin net - 1 and wig base resin net - 2 for wigs are as follows. [7] The wig base resin net according to [5] or [6] above, wherein when the mesh of the fabric is visually observed, the presence rate of the film peeling is 1 or less per 20 meshes. [8] The wig base resin net according to any one of [5] to [7] above, wherein the fabric having shape retention has heat resistance capable of maintaining the state of shape retention after being heated at 200 ° C for 10 minutes in a natural hanging state. [9] The wig base resin net according to any one of [5] to [8] above, wherein the fabric having shape retention is immersed in a methyl ethyl ketone (MEK) solution at room temperature for 5 minutes, taken out and dried at 50 to 60 ° C for 10 minutes, and then maintains the state of shape retention and has solvent resistance.

[10] The wig base resin net according to any one of [5] to [9] above, wherein the filament material constituting the fabric is made of nylon and / or polyester.

Effects of the Invention

[0019] According to the present invention, it is possible to solve the manufacturing means of the resin net for the Katsura tree base and the various technical problems described above that occur in the manufactured Katsura tree. Specifically, according to the present invention, the complicated procedures conventionally performed are simplified, and the resin net for the Katsura tree base can be manufactured in a simple method with fewer steps and without requiring complicated procedures, minimizing the generation of waste. Also, since it is possible to reduce the generation of harmful gases from the solvent used in the drying process, environmental problems can be considered. Moreover, a technique is provided that can make the obtained resin net for the Katsura tree base excellent in air permeability and exhibit good heat resistance, chemical resistance, etc. The above-described effects obtained by the present invention are achieved by skillfully using a low-molecular compound that can form a urethane bond (urethane resinification) or form a urea bond (urea resinification) to polymerize by generating a urethane bond that is configured not to react at room temperature, or a urea bond in a state where the low-molecular compound is impregnated into the filament material constituting the fabric, making it possible to generate a urethane bond or a urea bond.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic diagram for explaining the preparation procedures (a) to (c) of an evaluation sample used for a confirmation test for confirming that the net of the present invention has shape retention, and the outline (d) of an evaluation test using the evaluation sample.

Embodiments for Carrying Out the Invention

[0021] The present invention will be described in detail below with reference to preferred embodiments. The inventors of the present invention studied the prior art with a strong awareness of the usefulness of simplifying the complex procedures used in the production of conventional resin nets for the base of wigworts and finding a configuration that minimizes the waste generated by these complicated procedures. In addition to the above, the inventors of the present invention also studied the prior art with the recognition of the usefulness of studying the importance of selecting solvents that are of great significance in reducing environmental problems, and the rationalization of productivity that can be obtained by enabling the net, which is an intermediate processed product before becoming the final wig, to be stored for a long period of time without impairing the shape retention properties it has been given. Furthermore, the inventors of the present invention studied the prior art with the recognition that providing a highly breathable net and a wig with excellent breathability by improving the conventional method of using adhesives is an important improvement theme, and diligently studied the structure, production method, etc. of resin nets for the base of wigworts provided in the prior art.

[0022] The inventors of this invention, after diligently studying the prior art, have come to the realization that the thin film and the first net used in the prior art manufacturing method are both discarded after the process is completed, and that it would be extremely useful if the second net for the manufacturing purpose could be produced without using the thin film and the first net. In other words, the thin film is used to peel the first net from the male mold at the head, and the first net is used to absorb the coating liquid and prevent the formation of a resin film (skin) on the mesh of the final target product, the second net. Since both the first net and the thin film become waste after the process is completed, it would be extremely useful to be able to omit these formation steps in order to increase manufacturing efficiency and reduce waste.

[0023] The inventors have found that in order to omit the formation of the first net, it is necessary to provide a technology that can easily form a resin net for the base of a wig, which does not involve the formation of a resin film (skin covering) on ​​the mesh of the second net, which is the final target product and is made of a woven fabric such as nylon filament, and uses a net-like woven fabric as the base material, similar to that used in conventional second nets, and applies resin to the base material to provide good shape retention that matches the shape of the head. The inventors have diligently studied to make the above configuration possible and have found the configuration of the present invention, thereby realizing a resin net for the base of a wig that realizes the effects of the present invention.

[0024] The present invention relates to a resin net for wig bases-2, which is a resin net for wig bases formed of a net-like woven fabric having shape-retaining properties, wherein the filament material constituting the net-like woven fabric is impregnated with a urethane resin or urea resin, and the impregnated urethane resin or urea resin is characterized by being impregnated with a low molecular weight compound consisting of a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less and a low molecular weight polyisocyanate component with a molecular weight of 250 or less in which the isocyanate functional group is sealed with a blocking agent, and the net-like woven fabric is pressed onto a mold shaped like a head and the reaction product of urethane bonds or urea bonds generated by heat is characterized by the fact that the impregnated urethane resin or urea resin is impregnated with a low molecular weight compound consisting of a mixture of a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less and a low molecular weight polyisocyanate component with a molecular weight of 250 or less in which the isocyanate functional group is sealed with a blocking agent, and the net-like woven fabric is pressed onto a mold shaped like a head and the reaction product of urethane bonds or urea bonds generated by heat is characterized by the present invention relating to the present invention.

[0025] The Katsura resin net-1 of the present invention can be obtained by the method for manufacturing the Katsura resin net of the present invention, and is characterized in that the filament material constituting the net-like fabric is polymerized by the formation of urethane bonds or urea bonds, and the state of formation of said urethane bonds or urea bonds is configured such that the presence rate of film formation in the mesh of the net-like fabric is low, thereby giving the net-like fabric shape retention properties.

[0026] The resin nets for the base of Katsura plants according to the present invention, as described above, are all configured such that the rate of membrane formation in the mesh of the net-like fabric is low. For example, when the mesh of the fabric is observed visually, it is preferable that the rate of membrane formation is 1 or less per 20 meshes.

[0027] The resin nets for the base of Katsura trees according to the present invention, as described above, are characterized by their shape retention properties. The shape retention properties of the nets of the present invention were confirmed by the following method, as outlined in Figures 1(a) to (d). Specifically, first, as shown in (b), the fabric, which has been impregnated with the low molecular weight compound consisting of the mixed solution for 3 minutes, is cut into strips of 5 cm width and 20 cm length or longer and wrapped around the outer circumference of an annular aluminum bar (a) with a thickness of 2 mm and a square cross-section of 5 cm on each side. The excess portion that extends beyond the outer circumference of the bar is cut off (not shown), and the bar with the fabric wrapped around it is placed in a heating furnace and heated at 180°C for 10 minutes to generate urethane bonds or urea bonds. After generating urethane bonds or urea bonds, the sample for confirming and evaluating shape retention is removed from the heating furnace and allowed to return to room temperature. After returning to room temperature, as shown in (c), the fabric is released from the bar to obtain a net sample for confirming shape retention. Then, as shown in (d), one end of the demolded 5cm x 5cm x 5cm cube-shaped net sample is grasped and left to hang naturally, and the angle of the corner formed on the demolded net sample is measured using the aforementioned wooden block. The confirmation and evaluation of shape retention was performed by using the 90-degree angle of the wooden block as a reference, and ensuring that the measured angle of the corner formed on the net sample was within the range of 90 to 95 degrees.

[0028] The resin net for wig bases of the present invention described above can be easily obtained without complicated procedures by, for example, the method for manufacturing the resin net for wig bases of the present invention described below. That is, the manufacturing method of the present invention is a method for manufacturing a resin net for wig bases formed of a net-like fabric having shape retention properties, and is characterized by comprising: an impregnation step of impregnating the filament material constituting the net-like fabric with a low molecular weight compound consisting of a mixed solution having a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less, which does not react at room temperature and can generate urethane bonds or urea bonds when heated, and a low molecular weight polyisocyanate component with a molecular weight of 250 or less, in which the isocyanate functional group is sealed with a blocking agent; and a step of generating urethane bonds or urea bonds to impart the shape retention properties to the fabric by heating the fabric in which the filament material has been impregnated with the low molecular weight compound in the impregnation step while pressing it onto a mold that has been molded to resemble a head, thereby generating urethane bonds or urea bonds and polymerizing the fabric.

[0029] The background to the present invention is described below. The inventors diligently studied how to directly produce a second net in the conventional technology that has the desired shape retention, using a male mold molded from a head, and as a result found the following configuration. A low molecular weight compound that does not react at room temperature but can be polymerized by generating urethane or urea bonds when heated, and can become a urethane resin or urea resin, is impregnated into a filament material that constitutes a net-like fabric. It was found that by pressing this net onto a male mold molded from a head and heating it, the low molecular weight compound is polymerized by a reaction that generates urethane or urea bonds between the polyol component or polyamine component and the polyisocyanate component, thereby producing a urethane resin or urea resin. Preferably, by using a polyisocyanate component containing three or more isocyanate functional groups, a urethane resin or urea resin having a crosslinked structure can be produced. In the manufacturing method of the present invention with the above configuration, the process in which a specific low-molecular-weight compound impregnated between the filament materials forms urethane bonds or urea bonds and polymerizes to become a urethane resin or urea resin proceeds with a net-like fabric attached to a male mold shaped like a head, which is molded from the head. Therefore, the shape of the net after the reaction is completed inevitably conforms to the male mold, becoming similar to the second net in the prior art.

[0030] The low-molecular-weight compounds used above, which are precursors that can be polymerized to become urethane resin or urea resin, consist of a mixture of a polyol component or polyamine component and a polyisocyanate component. However, when both components are combined, a reaction immediately begins, increasing viscosity and making it extremely difficult to impregnate the filament material constituting the net-like fabric, as well as to achieve uniform coating. The inventors have diligently investigated this issue and have found that by using a low-molecular-weight polyisocyanate compound with a molecular weight of 250 or less as the polyisocyanate component, and encapsulating its isocyanate group with a blocking agent, and by also using a low-molecular-weight compound with a molecular weight of 250 or less for the polyol component or polyamine component, the viscosity of the mixture of both components can be kept low, thereby solving the above-mentioned problem.

[0031] As a result of diligent research, the inventors have found that by using the above-described uniquely configured mixed solution and impregnating the net-like woven filament material with the solution, the formation of a "film" in the mesh of the woven net can be effectively suppressed. Furthermore, by suppressing the formation of the above-described "film," the resulting net has improved heat permeability. In addition, the reason for using only low-molecular-weight compounds with a molecular weight of 250 or less when manufacturing the resin net for Katsura bedrock of the present invention is not only to prevent the formation of a "film" in the mesh, but also for the following reasons. According to the inventors' research, using compounds with a molecular weight greater than 250 results in the presence of long-chain inter-crosslink portions in the structure of the cross-linked polymer (resin), which makes the inter-crosslink chains more mobile, resulting in a soft and elastic texture, and thus potentially reducing the net's shape retention. It was necessary to avoid such problems.

[0032] The net material typically uses a plain weave of 220-330 denier filaments. The aforementioned specific low-molecular-weight compound mixture penetrates into these filaments, and the polymerization caused by heating through urethane or urea bonds occurs between the filaments, solidifying into urethane or urea resin in the areas where polymerization occurs. As a result, the resin net for the base of a wig according to the present invention is given and maintains the shape that is extremely important for a wig, conforming to the wearer's head. In contrast, conventional technology uses a highly viscous coating liquid that has already polymerized, so in this case, the urethane resin simply solidifies as a coating on the upper part of the filament weave. Thus, in conventional technology, since it becomes a coating of plastic urethane or urea resin on the upper part (surface) of the weave, shape retention is not maintained.

[0033] Furthermore, since the mesh spacing of the plain weave fabric is usually fine, at 15 to 50 mesh, conventional polymerized coating solutions tend to form a film between the meshes. For this reason, conventional techniques use a first net to eliminate this film formation. In contrast, the present invention involves impregnating a specific low-molecular-weight compound into the filaments of the fabric, then using heat to generate urethane or urea bonds to polymerize it, and finally solidifying it into a urethane or urea resin, thus virtually eliminating film formation.

[0034] Furthermore, in a preferred embodiment of the present invention, by appropriately selecting a polyisocyanate component and a polyol or polyamine component that are sealed with a blocking agent and used as a low molecular weight compound capable of producing urethane resin or urea resin, low boiling point soft solvents or alcohols can be used as solvents, thereby reducing the environmental problems that have been an issue in the prior art. In addition, the resin net for Katsura trees of the present invention, with the above-described configuration, eliminates the need to use a first net and a thin film of synthetic resin for release, which were required in the prior art, in its manufacturing process. This provides an extremely useful industrial effect, as the net can be efficiently manufactured using a simple procedure without complicated steps.

[0035] Furthermore, the unique low-molecular-weight compound that can produce urethane resin or urea resin, which is necessary when obtaining the resin net for the base of a wig according to the present invention, can maintain a state in which the isocyanate group, which is the active group (reactive group), is blocked for a long period of time even after impregnation into the net-like fabric that serves as the base material and removal of the solvent. Therefore, the resin net for the base of a wig according to the present invention has another significant advantage: when it becomes necessary to produce a net, it can be heated to induce a polymerization reaction and produce a urethane resin or urea resin, thereby providing shape retention. When making a wig product by implanting human hair or artificial hair into the resin net for the base of a wig according to the present invention, the adhesive can be applied to the entire back surface after the human hair or artificial hair has been implanted, or the adhesive can be applied in dots only to the implanted hair area to ensure suitable breathability of the wig.

[0036] Furthermore, the resin net for wig bases of the present invention allows for the application of new methods, such as those listed below, when manufacturing wig products. In the case of conventional nets, hair is implanted into a three-dimensional resin net for wig bases (wig base) obtained by pressing it into a mold, and because the net is three-dimensional, the implantation process is done manually. In contrast, by using the resin net for wig bases with the configuration of the present invention, it is possible to implant human hair or artificial hair into a flat net that has been pre-impregnated with a low-molecular-weight compound using a simple method, and then press it into a mold and heat it to produce a three-dimensional wig without going through the net stage. Thus, the manufacturing method of the present invention is useful because it greatly simplifies wig production. Furthermore, in the manufacturing method of the present invention, polymerization (resinization) is performed while the low-molecular-weight compound is impregnated into the fabric, so there is no need to weld the intersections of the filament mesh of the fabric using ultrasonic welding, as is done in conventional technology, and it has the advantage of being able to be tightly bonded.

[0037] Methods for blocking the reactive functional groups of polyisocyanate components are widely used in fields such as high-solids coatings, powder coatings, and water-based coatings. Various compounds with diverse structures, such as phenols, alcohols, oximes, and lactams, are used as blocking agents. Commonly used in the coating field include, for example, 2-butanone oxime (also known as methyl ethyl ketoxime, hereinafter abbreviated as MEKO), dimethylpyrazole (hereinafter abbreviated as DMP), malonic acid diesters, and caprolactam, all of which can be used. These blocking agents each exhibit different dissociation temperatures. For example, according to catalogs, MEKO is 160°C, DMP is 120°C, and caprolactam is 170°C. Furthermore, dibutyltin dilaurate is said to exhibit catalytic effects. As will be described later, MEKO and DMP were used as blocking agents in the examples of the present invention, but the present invention is not particularly limited to these.

[0038] Polyisocyanate components, which are used by blocking reactive functional groups, include a wide variety of aromatic and aliphatic compounds, and the number of isocyanate functional groups also varies. In this invention, since it is for wigs, the focus is on aliphatic polyisocyanates, which have excellent light resistance. Examples of aliphatic polyisocyanates include bifunctional types such as hexamethylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, or adducts thereof, such as the trimer of hexamethylene diisocyanate. However, diisocyanates have a low boiling point, are highly volatile, and are known to cause skin allergies, so they are not very desirable in terms of the process. In this invention, it is preferable to use a polyisocyanate component that contains an isocyanate content of 17% to 25% in the molecule, has 3 or more isocyanate functional groups, and has a molecular weight of 250 or less.

[0039] When using diisocyanates as the polyisocyanate component in the present invention, their polymers are suitable. Examples of polymers include adducts obtained by adding a diisocyanate monomer to a polyhydric alcohol, isocyanurates (trimers), and biuret compounds. The polymer can be produced by any of the biuret reaction, isocyanurate reaction, or adduct reaction. In the present invention, a polymer with an isocyanate (NCO) content of 17% to 25% on a solids basis is used as a suitable low-molecular-weight polyisocyanate compound. Such compounds are commercially available, and examples include Coronate HX, Coronate HK, Coronate HXR, Coronate 2770, Coronate 2793 (trade names, all manufactured by Tosoh Corporation), and Duranate 24A100, Duranate TMA100, TPA100, TKA100 (trade names, all manufactured by Asahi Kasei Corporation).

[0040] The polyol and / or polyamine components used in the present invention can also be bifunctional or trifunctional low molecular weight alcohols and / or low molecular weight amines. Using a polyol or polyamine component with a molecular weight of 250 or less is preferable from the viewpoint of viscosity. Examples of such polyols include bifunctional alcohols such as 1,4-butanediol, ethylenediol, propylenediol, diethylene glycol, and dipropylene glycol; trifunctional alcohols such as glycerin and trimethylolpropane; and tetrafunctional alcohols such as pentaerythritol; all of which can be used. In addition to these alcohols, low molecular weight diamines and triamines with a molecular weight of 250 or less, which react with isocyanate functional groups, may be partially used to improve heat resistance and generate urethane and urea bonds to form urethane urea. However, this tends to reduce the light resistance of the resulting urethane resin, and caution is required in handling due to its toxicity. Of course, a small amount of a compound with a molecular weight of 250 or more may be used in addition to the above low molecular weight compounds for purposes such as viscosity adjustment, as long as the curing of the invention is not impaired.

[0041] According to the inventors' studies, when a low-molecular-weight compound capable of producing a urethane resin or urea resin is reacted and polymerized, if the resulting urethane resin or urea resin exhibits plasticity, the manufactured net will have poor shape retention, which is undesirable. Specifically, if the polyisocyanate component and the polyol component or polyamine component constituting the present invention are both bifunctional, the resulting urethane resin or urea resin will be plastic, which is unsuitable. It is suitable to use a combination in which either or both of the polyisocyanate component and the polyol component or polyamine component have three or more functional groups, based on the number of isocyanate functional groups and the number of alcohol or amine functional groups.

[0042] In the embodiments of the present invention described later, the polyisocyanate component used was Coronate HX (trade name, trimer of hexamethylene diisocyanate), which has three isocyanate functional groups. The polyol component used was either trimethylolpropane (hereinafter abbreviated as TMP), which has three alcohol functional groups, or 1,4-butanediol (hereinafter abbreviated as BD), which has two alcohol functional groups. The polyamine component used was either monoethanolamine (hereinafter abbreviated as MEA), which has one alcohol functional group and one amine functional group, or ethylenediamine (hereinafter abbreviated as EDA), which has two amine functional groups. A mixed solvent of toluene and isopropyl alcohol in an equivalent mass ratio was used as the solvent for dissolving both components. Using a mixed solvent reduces the amount of toluene used. Note that the above combinations are representative examples, and the present invention is not limited to these.

[0043] In the resin net for the base of a wisteria tree according to the present invention, examples of the net-like woven fabric used as the base material include a woven fabric made of nylon filament material with a density of 220 denier to 330 denier. [Examples]

[0044] Next, the present invention will be described in more detail with reference to examples and comparative examples. Unless otherwise specified, the term "parts" in this text refers to parts by mass. [Examples] <Preparation of coating and impregnation solutions> (Preparation of low molecular weight compounds) 100 parts of Coronate HX (trade name, manufactured by Tosoh Corporation, NCO content 20.5-22.0%) were dissolved in 100 parts of toluene and diluted to prepare Coronate HX solution. Equimolar amounts of methyl ethyl ketoxime (MEKO) or dimethylpyrazole (DMP) were added as blocking agents to the isocyanate groups (NCO groups) of this Coronate HX solution to block the NCO groups of Coronate HX, respectively. The blocking reaction was carried out at room temperature, and the success or failure of the blocking was confirmed by the disappearance of the isocyanate groups using a Fourier transform infrared spectrometer (FT-IR). After the reaction was complete, 100 parts of isopropanol were added to the reaction product to prepare MEKO-blocked polyisocyanate solution and DMP-blocked isocyanate solution, respectively. The calculated molecular weight of the Coronate HX used above is 190-205.

[0045] On the other hand, 100 parts of trimethylolpropane (TMP) were dissolved in a mixed solvent of 150 parts of toluene and 150 parts of isopropyl alcohol to prepare a polyol solution with three alcohol functional groups. In the same manner, a polyol solution of 1,4-butanediol (BD) with two alcohol functional groups, a monoamino alcohol solution of monoethanolamine (MEA) with one alcohol functional group and one amine functional group for a total of two functional groups, and a polyamine solution of ethylenediamine (EDA) with two amine functional groups were prepared.

[0046] Next, the two types of block isocyanate solutions prepared earlier were used with the polyol solution, polyamine solution, and monoamino alcohol solution prepared above, respectively, and the mixtures were prepared so that the block isocyanate groups and alcohol functional groups and / or amino groups were in equal molar proportions. Furthermore, the solid content in the mixture was diluted to a predetermined concentration with a mixed solvent of toluene and isopropyl alcohol to obtain the coating and impregnation solutions used in the examples of the present invention. The composition of the low molecular weight compounds used is summarized in Table 1. During dilution, the solvent composition in the diluted coating and impregnation solution was adjusted so that the mass ratio of toluene to isopropyl alcohol was 50 / 50.

[0047] (Viscosity of coating / impregnation solutions containing low molecular weight compounds) The viscosity of the diluted solution (coating / impregnation solution) with the solid content adjusted to the predetermined concentration as described above was measured at 20°C using a BL-type viscometer. This viscosity value, along with the viscosity value after 8 hours of mixing, is summarized in Table 1 as a reference value.

[0048] (fabric) The fabric used was a plain weave made from 250-denier nylon filament material.

[0049] <Methods for impregnation of textiles and testing methods for heat treatment> (Regarding impregnation of textiles) The fabric was cut into 5 x 22 cm strips and immersed at room temperature for 3 minutes in each coating / impregnation solution containing the block polyisocyanate component, polyol component, and / or polyamine component as described in Table 1. After 3 minutes, the fabric was removed, excess liquid was allowed to drain naturally, and the fabric was air-dried. The mass of the fabric before immersion in the coating / impregnation solution was also measured. Furthermore, the mass of the fabric after immersion in each coating / impregnation solution and drying was measured, and the amount of coating / impregnation solution adhering to the nylon filament of the fabric was determined by comparing it with the mass of the fabric before the test. The results are summarized in Table 1.

[0050] (Method for imparting shape retention to textiles impregnated with a coating or impregnation solution) After immersing the fabric in each of the coating / impregnation solutions prepared earlier as shown in Table 1, the fabric was air-dried, and then lightly wrapped around the outer circumference of an annular aluminum bar with a thickness of 2 mm and a cross-sectional shape of a 5 cm square. The excess portion extending beyond the circumference of the bar was cut off, and the annular bar with the fabric wrapped around it was placed in a heating furnace and heated at 180°C for 10 minutes. After removing it from the furnace and allowing it to cool to room temperature, the fabric was released from the bar and used as a test sample to evaluate the degree of shape retention (see Figure 1).

[0051] <Evaluation of textiles impregnated with coating / impregnation solutions> (Tests and evaluation criteria for determining shape retention) To evaluate the shape retention properties of the fabric, a shape (corner) was imparted to the fabric using the method described above with an aluminum ring-shaped bar. One end of the test sample obtained by heating was grasped and left to hang naturally. The angle of the corner of the naturally hanging fabric was measured using the angle of the bar used to prepare the test sample (90 degrees) as a reference, and the results are summarized in Table 2. A sample was evaluated as passing if the measured angle was within the range of 90 to 95 degrees, and as failing otherwise.

[0052] (Evaluation of the state of membrane formation) For the test specimens prepared earlier to evaluate the shape retention properties, 20 meshes at arbitrary locations were visually observed to confirm the number of films formed due to the heating of the coating / impregnation solution. The results of the confirmed number are summarized in Table 2. A sample with one or fewer films formed was evaluated as a pass, and any other was evaluated as a fail.

[0053] (Heat resistance evaluation test) The test samples prepared earlier to evaluate the shape retention properties were subjected to a heat resistance test using the following method. Similar to the shape retention test, one end of the woven test sample was grasped and suspended in a 200°C oven for 10 minutes to perform the heat resistance test. Using the angle of the square timber used to prepare the test sample (90 degrees) as a reference, the angle of the corner formed on the naturally suspended woven fabric was measured, and the results are summarized in Table 2. Samples that maintained an angle of 90 to 95 degrees at the corner of the naturally suspended woven fabric after the heat resistance test were evaluated as passing, and all others were evaluated as failing.

[0054] (Solvent resistance test) The test samples prepared earlier to evaluate the shape retention properties were subjected to solvent resistance testing using the following method. The passable test samples for shape retention were immersed in MEK at room temperature for 5 minutes, then removed from the MEK and dried at a temperature of 50°C to 60°C for 10 minutes. The dried samples obtained in this way were subjected to the same procedure as the test to evaluate the shape retention properties. The angle of the corners formed on the naturally suspended fabric was measured using the angle of the square timber used in the preparation of the test samples (90 degrees) as a reference, and the results are summarized in Table 2. Samples that maintained an angle of 90 to 95 degrees at the corners formed on the naturally suspended fabric after the solvent resistance test were evaluated as passable, and all others as failing.

[0055] [Comparative Examples 1 and 2] As a comparative example, a comparative coating solution was prepared using a commercially available, non-yellowing polyurethane resin suitable for thin film formation and applications requiring discoloration resistance as a surface material. This solution was then coated onto a fabric to obtain test specimens. Specifically, non-yellowing thermoplastic polyurethane resin solutions (using a mixed solvent of toluene / isopropyl alcohol = 50 parts / 50 parts) such as Rezamin NE302 or Rezamin NE308 (trade names, both manufactured by Dainichi Seika Kogyo Co., Ltd.) were used. As shown in Table 1, the example using Rezamin NE302 was designated as Comparative Example 1, and the example using Rezamin NE308 was designated as Comparative Example 2. The solutions were then diluted to a predetermined concentration with a mixed solvent having the same solvent composition as the resins to obtain two different concentrations of polyurethane resin coating solutions for Comparative Examples 1 and 2, respectively. The obtained coating solutions were applied to the fabric, dried, and test samples were obtained. The same evaluation tests as those performed in the examples were then conducted using the obtained test samples.

[0056] TIFF2026052519000001.tif166170

[0057] TIFF2026052519000002.tif165170

[0058] As shown in Table 2, the comparative example net, obtained by coating a fabric with a coating solution containing polyurethane resin, exhibited inferior shape retention compared to the example net. Furthermore, in the examples of the present invention, no "film formation" was observed in the mesh of the fabric in any of the test samples with solid content of 1%, 5%, and 10%. In contrast, in the comparative example net, while no "film formation" was observed in the mesh of the fabric in the test sample using a coating solution with 1% solid content, approximately 20 "film formations" were observed in 20 meshes in the test sample with 10% solid content. This indicates that the net had poor breathability. As shown in Table 2, in the examples of the present invention, good results were obtained in the heat resistance test and solvent resistance test in any of the test samples with solid content of 1%, 5%, and 10%. In contrast, in the comparative example, while the test samples using coating solutions with a solid content of 1% and 10% performed better than those using only fabric, it was confirmed that they exhibited inferior heat resistance and solvent resistance compared to the examples of the present invention.

Claims

1. A method for manufacturing a resin net for the base of a wisteria, which is made of a net-like woven fabric having shape-retaining properties, An impregnation step in which a low molecular weight compound is impregnated into the filament material constituting the net-like fabric with a mixture of a low molecular weight compound comprising a polyol component or polyamine component with a molecular weight of 250 or less, which does not react at room temperature and can generate urethane bonds or urea bonds when heated, and a low molecular weight polyisocyanate component with a molecular weight of 250 or less, in which the isocyanate functional group is encapsulated with a blocking agent. A method for manufacturing a resin net for a wig base, characterized by comprising a step of generating urethane bonds or urea bonds to impart shape retention to the fabric, wherein the fabric, in which the filament material has been impregnated with the low molecular weight compound in the impregnation step, is heated while being pressed onto a mold shaped like a head, and the heating generates urethane bonds or urea bonds to polymerize the fabric.

2. A method for producing a resin net for Katsura plateaus according to claim 1, wherein the low molecular weight compound comprises a polyol component and / or polyamine component having two or more alcohol and / or amine functional groups and a molecular weight of 250 or less, and a polyisocyanate component having three or more isocyanate functional groups, having an isocyanate content of 17% or more and 25% or less in the molecule and a molecular weight of 250 or less, and wherein the isocyanate functional groups are sealed with a blocking agent.

3. A method for manufacturing a resin net for a wisteria base according to claim 1 or 2, wherein the filament material constituting the fabric is made of nylon and / or polyester.

4. The method for manufacturing a resin net for a Katsura tree base according to claim 1 or 2, wherein the shape retention is confirmed by wrapping the fabric, which has been impregnated with the low molecular weight compound consisting of the mixed solution for 3 minutes, in strips of 5 cm width and 20 cm length or longer, around the outer circumference of an annular aluminum rod having a thickness of 2 mm and a square cross-section with sides of 5 cm, and cutting off any excess portion that extends beyond the outer circumference of the rod, and then placing the rod with the fabric wrapped around it into a heating furnace and heating it at 180°C for 10 minutes to generate urethane bonds or urea bonds, and then removing the sample for shape retention evaluation from the heating furnace and returning it to room temperature, releasing the fabric from the rod, grasping one end of the released 5 cm x 5 cm x 5 cm cube-shaped fabric and letting it hang naturally, measuring the angle of the corner formed on the released fabric by the rod, and confirming that the measured angle is within the range of 90 degrees to 95 degrees, with the 90-degree angle of the rod as the reference.

5. A resin net for a Katsura tree base obtained by the method for manufacturing a Katsura tree base according to claim 1 or 2, A resin net for Katsura trees, characterized in that the filament material constituting the net-like fabric is polymerized by the formation of urethane bonds or urea bonds, and the state of formation of the urethane bonds or urea bonds is configured such that the presence rate of film formation in the mesh of the net-like fabric is low, thereby giving the net-like fabric shape retention properties.

6. A resin net for the base of a Katsura tree, formed from a net-like woven fabric having shape-retaining properties, A resin net for wig bases, characterized in that the net-like fabric is formed by impregnating a filament material constituting the net-like fabric with a urethane resin or urea resin, and the impregnated urethane resin or urea resin is impregnated with a low molecular weight compound comprising a mixture of a low molecular weight polyol component or polyamine component with a molecular weight of 250 or less and a low molecular weight polyisocyanate component with a molecular weight of 250 or less in which the isocyanate functional group is sealed with a blocking agent, and the net-like fabric is pressed onto a mold shaped like a head and the reaction product of urethane bonds or urea bonds generated by heat is the result of heating.

7. The resin net for the base of a Katsura tree according to claim 5 or 6, wherein, when the mesh of the fabric is observed visually, the presence rate of the membrane is 1 or less per 20 meshes.

8. The resin net for the base of a Katsura tree according to claim 5 or 6, wherein the shape-retaining fabric is in a heat-resistant state that can maintain its shape-retaining state after being heated at 200°C for 10 minutes in a naturally suspended state.

9. The resin net for the base of a wisteria tree according to claim 5 or 6, wherein the woven fabric having the shape retention properties maintains its shape retention and is solvent-resistant after being immersed in a methyl ethyl ketone (MEK) solution at room temperature for 5 minutes, removed, and dried at 50-60°C for 10 minutes.

10. The resin net for the base of a wisteria according to claim 5 or 6, wherein the filament material constituting the fabric is made of nylon and / or polyester.

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