Pre-UV Protection Additive for Raw Land and Method of Use

Abstract

The present invention relates to a UV-protective fabric comprising a sheet substrate containing synthetic, semi-synthetic, or natural fabric or a mixture thereof, a UV-absorbing chemical substance present on the substrate, and a capping agent bonded to the UV-absorbing chemical substance, and a method for producing the UV-protective fabric. The UV-absorbing chemical substance may be, for example, an organic acid such as tannic acid, a protein, a flavonoid, or a polyphenol compound. The capping agent may be an alkylbenzene-based surfactant, a phenylethanoid, a monophenol, or a protein such as whey or casein, for example.

Description

Background Art

[0001] Ultraviolet (UV) rays damage cells and, when exposure lasts for a long time, are the main cause of skin cancer worldwide. Damage caused by UV rays appears as dry skin and premature skin aging, and may also cause eye diseases such as cataracts. Since UV rays have high energy, they can penetrate clouds, reflect off snow, and even pass through windows and windshields. To reduce the damage caused by exposure to UV rays, doctors recommend using sunscreen with at least SPF15, and in many cases SPF30, and reapplying it every two hours.

[0002] Sun protection clothing is another important means to protect the body from the harm of ultraviolet rays. The performance of clothing that blocks ultraviolet rays is described as the Ultraviolet Protection Factor (UPF). According to the Skin Cancer Foundation, the UPF indicates the amount of ultraviolet rays that reach the skin through the fabric. For example, a fabric with a UPF of 50 blocks 98% of sunlight and allows 2% (1 / 50) to pass through, significantly reducing the risk of exposure to ultraviolet rays. A high UPF value can be achieved in various ways, but the most important are color, structure, and content. Usually, when dyes are added to the fabric, the UPF performance of the resulting product improves depending on the nature of the added dyes. Organic dyes are generally aromatic compounds or contain one or more benzene rings and are known to absorb ultraviolet rays. Over time, the skeletons of these compounds are destroyed by absorbing these high-energy rays, generally resulting in a state called "sun bleaching." The structure of the fabric is equally important. The denser the weave and the thicker the fibers, the higher the effect of blocking ultraviolet rays. Unfortunately, ultraviolet rays tend to be most abundant on sunny afternoons from 10 am to 4 pm, so thick shirt fabrics and fabrics are not very preferable in hot climates. To overcome this limitation, clothing items with different fiber contents are adopted. Synthetic fibers such as polyester, nylon, and acrylic are formed from long polymer chains formed from resins. These chains often contain benzene rings and absorb ultraviolet rays as described above. Due to this inherent protective function, the majority of the outdoor fabric market is occupied by synthetic fibers or blends with natural fibers. However, only about one-third of summer clothing has a UPF of 15 or higher.

[0003] Current approaches to improving the UPF of natural fibers rely on chemical additives or surface treatments. Some research groups have shown the potential of cotton fibers coated with thin graphene layers, which absorb incident ultraviolet light and help improve the performance of the fabric. Although promising, there is little possibility that this type of manufacturing method can be scaled up to the levels required in the fiber industry. Other techniques have also been developed, such as the surface functionalization of fibers with titanium dioxide nanoparticles, a common metal oxide additive used in sunscreens, due to their ability to absorb ultraviolet light. Although other nanoparticles or surface coatings have been studied by numerous institutions, the main barrier is the ability to bind the active agent to the surface. In most treatment methods, after several washes, the agent is washed out of the fabric, not only reducing the UPF to its original level but also contaminating the wastewater with the applied active agent. In terms of scalability and ease of use, chemical additives seem to be superior. As mentioned above, organic dyes often have excellent ultraviolet absorption properties, and natural alternatives such as flavonoids and polyphenols are attractive options. Some research groups have also used rutin, a natural flavonoid derived from plants such as citrus fruits, to improve the ultraviolet protection properties of silk fibers. Unfortunately, none of these methods utilize compounds that do not absorb in the visible spectrum, which would effectively discolor the underlying fabric in some way. Therefore, the usefulness of chemical additives is limited. Improvements are needed to enhance the ultraviolet protection effect of fabrics. Summary of the Invention Means for Solving the Problems

[0004] Various embodiments include ultraviolet (UV) protective fabrics. In some embodiments, the UV protective fabric includes a sheet substrate comprising a synthetic, semi-synthetic, or natural fabric or a mixture thereof, a UV absorbing chemical present in the substrate, and a capping agent bonded to the UV absorbing chemical. The UV absorbing chemical may be, for example, an organic acid, protein, flavonoid, or polyphenol compound. In some embodiments, the UV absorbing chemical is an aromatic acid. In some embodiments, the UV absorbing chemical is gallic acid, tannic acid, salicylic acid, caffeic acid, dopamine, or ferulic acid. In other embodiments, the UV absorbing chemical is tannic acid. In some embodiments, the capping agent is an alkylbenzene surfactant, phenylethanoid, monophenol, or protein. The capping agent may be, for example, a natural-derived protein such as whey or casein.

[0005] The UV protective fabric can be made into clothing configured to be worn on a user's body. The coverage rate can exceed 97%.

[0006] The UV protective fabric can be an organic porous body. The organic porous body also includes inorganic components in the form of nanoparticles, coatings, or fibers.

[0007] Various embodiments include methods for manufacturing UV protective fabrics. In some embodiments, the method includes applying a UV absorbing organic compound in solution to a porous body, diffusing the UV absorbing organic compound into the porous body, and drying the porous body coated with the UV absorbing organic compound solution to bind the compound to the surface of the porous body and the fibers inside the material. In some embodiments, drying the porous material includes heating the porous body. The UV absorbing organic compound may be, for example, tannic acid.

[0008] In some embodiments, the method includes applying a capping agent in solution to the porous body before or after drying the porous body after applying the ultraviolet protection material, and diffusing the capping agent into the porous body. When applying the capping agent after drying the porous body, the method may further include drying the porous body having the applied capping agent after applying the capping agent to bind the capping agent to the ultraviolet absorbing compound. The capping agent may be a protein of natural origin such as a casein salt. The porous body may be a fabric.

Brief Description of the Drawings

[0009] This specification particularly points out and distinctly claims the subject matter regarded as forming various embodiments of the present disclosure, but the present disclosure is considered to be better understood by reading the following description in conjunction with the accompanying drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0018] This application claims the benefit of U.S. Provisional Application No. 63 / 338,092, filed May 4, 2022, entitled “Pre-Ultraviolet Protection Additive for Fabrics and Methods of Preparation and Use Thereof,” which is hereby incorporated by reference in its entirety.

[0019] The various inventions described herein include fabrics that block ultraviolet light and methods of manufacturing the same. Various embodiments include chemical additives and application steps that increase the UPF value of a fabric, including a fabric containing natural cellulose fibers, without discoloring the fabric. The wet chemical additive can be applied to the fabric and allowed to penetrate the fabric, such as by spraying the fabric or immersing the fabric in a chemical bath. The fabric can then be dried, such as by heating the fabric, until completely dry to fix the chemical to the yarn. In some embodiments, multiple chemical additives can be applied to the fabric, for example, in a continuous process, and the fabric can be optionally dried between applications of the chemical.

[0020] The fabric processed as described herein has an improved ability to absorb ultraviolet rays from the sun. In various embodiments, the chemical additive is a soluble functional compound, which is applied to the fabric surface and then heated until dried, and the functional compound binds to the fabric via a force such as ionic force, preventing its release during washing. The resulting fabric has the added ultraviolet protection function for the user while maintaining the physical properties of the original fabric.

[0021] The chemical additives used for the purpose of fabric treatment according to various embodiments improve the ability to block ultraviolet rays in the fabric and protect the user. In various embodiments, the chemical additive comprises a first composition and a second composition. The first composition may include one or more ultraviolet blocking compounds having known absorption peaks in the ultraviolet range and / or significant absorption in the ultraviolet range. The second composition may include one or more capping compounds. The capping compound can react with the first composition to ensure the stability of the first composition on the substrate. For example, the capping compound can be selected to form a chemical bond with the exposed reactive sites on the ultraviolet blocking compound bound to the substrate. In this way, the capping compound can prevent the binding of other compounds, such as inorganic compounds and / or other compounds, to the ultraviolet blocking compound, which otherwise may cause changes in the absorption of the ultraviolet blocking compound and / or discoloration of the underlying substrate.

[0022] A representative view of the substrate of the fabric processed according to various embodiments is shown in FIG. 1. The processed fabric 10 includes a fabric substrate 12 coated with an ultraviolet blocker 14. A capping agent 16 is bound to the ultraviolet blocker 14. In this way, the capping agent 16 reduces or prevents the reactive sites present in the ultraviolet blocker 14 from reacting with other compounds that may interfere with its ultraviolet blocking performance. In FIG. 1, the fabric substrate 12, the ultraviolet blocker 14, and the capping agent 16 are depicted as separate layers, but it should be understood that FIG. 1 is merely conceptual. In reality, the blocker 14 and the capping agent 16 penetrate the fabric substrate 12 and its fibers and bind uniformly throughout the fibers.

[0023] In some embodiments, the second composition can be omitted. For example, when the substrate does not need to maintain white or substantially white, or when the color change caused by the use of the first composition is not important, or when the color change caused by the first composition is not a concern, such as when desired, the second composition may not be necessary.

[0024] The first composition can include one or more compounds. For example, the first composition can include one or more ultraviolet absorbing chemical substances, such as a mixture of ultraviolet absorbing chemical substances. The chemical substances that can be included in the first composition can include one or more of organic acids, proteins, flavonoids, and / or polyphenol compounds, which can be combined with one or more stabilizers, such as organic and / or inorganic stabilizers including sodium phosphate, alginate, and sucrose, but not limited thereto.

[0025] The ultraviolet absorbing compound included in the first composition can have the ability to absorb ultraviolet radiation through reactive groups including, but not limited to, aromatic rings and conjugated double bonds. Examples of ultraviolet absorbing polyphenol compounds included in the first composition include, but are not limited to, gallic acid, tannic acid, dopamine, caffeic acid, salicylic acid, ferulic acid, and other aromatic acids. Examples of capping compositions included in the second composition include organic and inorganic capping agents such as alkylbenzene-based surfactants, phenylethanoids such as tyrosol, natural monophenols such as carnosol, and natural-derived proteins such as whey and casein, but not limited thereto.

[0026] An example of the treated fiber 20 is shown in FIG. 2. The treated fiber 20 includes a fiber 22, an ultraviolet blocker 24, and a capping agent 26. In this example, the hydroxy group of the ultraviolet blocker 24 binds to the R group of the fiber 22 to cover the fiber 22, providing ultraviolet protection to the fiber 22. The other hydroxy groups of the ultraviolet blocker 24 that did not bind to the fiber 22 bind to the capping agent 26. By binding the capping agent 26 to the released hydroxy group, the released hydroxy group of the ultraviolet blocker 24 is blocked from other interactions such as interactions that may cause discoloration and / or interfere with the ultraviolet blocking ability.

[0027] Without using a capping agent, all of the unbound hydroxy groups (and / or other reactive groups) of the ultraviolet blocker remain open and may interact with components in, for example, a detergent, causing significant discoloration of the fiber. The use of a capping agent blocks access to some or all of the reactive groups of the ultraviolet blocker, reducing or preventing interactions with other compositions and the resulting discoloration. Thus, the use of a capping agent allows the use of an ultraviolet blocker even in materials where the use of an ultraviolet blocker has been avoided because the material would ultimately discolor.

[0028] A variety of materials can serve as the substrate to be functionalized using the methods described herein. The ultraviolet blocking compound can form an effective bond with the active ultraviolet blocker using the oxygen, nitrogen, or hydrogen functional groups of the material. Materials that do not have these surface groups, such as metals, some plastics, glass, etc., are not affected by the treatment.

[0029] The processes described herein provide protection from ultraviolet light to the material itself and to the user, and the resulting user ultraviolet protection depends on the form of the final product, including but not limited to fiber density, coverage, and mixing of materials. In some embodiments, the treated knit or woven fabric has a coverage of from about 97% to about 100%.

[0030] In some embodiments, the processed material is porous, while in other embodiments, the processed material is non-porous. The processed material can be a synthetic or natural fabric, non-woven fabric, fiber, or microfiber, including synthetic, semi-synthetic, or natural woven fabrics. Examples of usable fabrics include cotton, polyester, nylon, spandex, rayon, linen, cashmere, silk, wool, acrylic, modacrylic, olefin, acetate, polypropylene, polyvinyl chloride, lyocell, latex, and aramid, as well as blends or combinations of one or more of these or other materials or other fibers. Thus, the fabric can be natural, such as silk, wool, cotton, cellulose derivatives, linen, jute, or bamboo, or a polymer such as nylon, polyester, acrylic, spandex, rayon, polypropylene, polyurethane, or a combination of two or more of these. In some embodiments, the material can be a fabric that is a blend of different materials including those listed above.

[0031] In some embodiments, the processed material can be a sheet. The sheet can be composed of organic and / or inorganic components. In some embodiments, the organic material sheet can be a paper material. In some embodiments, the organic material sheet can further include inorganic components in the form of, for example, nanoparticles, coatings, and / or fibers.

[0032] In some embodiments, the first composition and any second composition can be combined with a porous support material, such as a sheet-like material like a fabric. The porous support material can be cotton, cellulose, viscose, silk, aramid, nylon, polypropylene, polystyrene, polyester, polyurethane, polyamide, polyethylene, polycarbonate, or a combination of two or more of these or other materials disclosed herein. This combination can be obtained, for example, by covalent bond interactions, hydrogen bonds, or electrostatic interactions.

[0033] In some embodiments, a treated material comprising a sheet having a binding composition is an ultraviolet resistant sheet that can be used as a product or as a component of a product. The ultraviolet resistant sheet may be provided as a single, double, triple, or greater number of sheets arranged alone or laminated with other ultraviolet resistant sheets or other sheets or materials.

[0034] Treated materials according to various embodiments can be used as ultraviolet protective clothing such as hats, shirts, pants, jackets, scarves, and swimwear. In other embodiments, the ultraviolet protection of the treated material can reduce or prevent damage to the material itself by ultraviolet light, such as reducing or preventing color fading due to ultraviolet light in products used outdoors and / or products exposed to sunlight. In some of such embodiments, the treated material can be used, for example, as upholstery for furniture, interior materials for automobiles or other vehicles, tents, waterproof sheets, umbrellas, towels, blankets, bedding, curtains and other window decorations, and sunshades.

[0035] An example of a functionalization process 30 for producing an ultraviolet resistant material is shown in FIG. 3. In a first step 32, a first composition containing an ultraviolet blocker is impregnated into a material such as a fabric to impregnate the material with the composition. The impregnation of the ultraviolet absorbing organic chemical into the fabric can be carried out, for example, by dipping or spraying. In some embodiments, the first composition is a suspension or solution such as an aqueous suspension or aqueous solution having a concentration in the range of about 0.005% to about 5%, or about 0.5% to about 2%, for example about 0.8% or about 2% based on the weight of the composition. In many embodiments the composition is aqueous, but alternatively it may be non-aqueous such as a dilute solution (less than 50% or less than 25% etc.) of an organic solvent such as acetone, ethanol, isopropanol. The step of applying the first composition to the fabric may include impregnating the fabric with the composition by dipping the fabric into the first composition or spraying the first composition onto a support material.

[0036] In the second step 34, the second composition containing the capping agent is impregnated into the fabric. Similar to the first step 32, the impregnation with the second composition can be carried out, for example, by dipping or spraying. In some embodiments, the composition is a suspension or solution, such as an aqueous suspension or aqueous solution, having a concentration in the range of about 0.05% to about 15%, or about 1% to about 4%, for example about 2.5% or about 3%, based on the weight of the composition. In many embodiments, the composition is aqueous, but alternatively, it may be non-aqueous, such as a dilute solution (less than 50% or less than 25%) of an organic solvent such as acetone, ethanol, isopropanol. The step of applying the composition to the material may include impregnating the support material with the composition, such as by dipping the material into the composition or spraying the composition onto the support material.

[0037] In the third step 36, the fabric is dried by heating or the like, and the composition is bonded to the fabric or the compositions are bonded to each other. For example, the composition can be bonded to the fabric by drying and / or by heating such as using a heat dryer. The heating process can be carried out, for example, within the range of about 50°C to about 150°C, depending on the thermal stability of the material of the substrate to be treated. The heat causes the solution to evaporate and initiates a chemical bond between the substrate and the ultraviolet blocking compound and the capping agent.

[0038] Although not shown in FIG. 3, the functionalization process can also include an additional intermediate drying step after the first step 32 and before the second step 34. That is, after impregnating the first composition into the material, the material can be dried by applying heat or the like, and the ultraviolet blocking agent can be bonded to the material. This heating is as described above with respect to the third step in FIG. 3. Next, the second composition can be impregnated into the material containing the bonded ultraviolet blocking agent and dried as described above with respect to steps 2 and 3 in FIG. 3.

[0039] In some embodiments, the process of functionalizing the material with the UV-blocking compound can be carried out on a large scale using a continuous process, such as the process shown in FIG. 4. The support material 42 can be continuously conveyed, such as on a conveyor belt of a manufacturing line. In this example, the process starts with the support material before the process on the left side. As the support material is conveyed from left to right, the first composition 44 containing the UV-blocking solution is applied to the material 42 by spraying, and then, as the material 42 continuously progresses along the line, the second composition 46 containing the capping agent solution is applied by spraying. The impregnated support material is then conveyed through the heating element 48 to bind the UV-blocking compound to the support material and to bind the capping agent to the UV-blocking compound. The processed material after the process exits from the right side of the manufacturing line and can be used for the production of products.

[0040] In various embodiments, commercial or industrial dryers that can dry large amounts of material, such as large amounts of fabric, and can operate for longer periods, such as continuously throughout the day, can be used. For example, such commercial dryers may have a large drying cylinder size, a high air flow rate, and a high BTU rating, which can help shorten the drying time and increase the drying efficiency. In some embodiments, the dryer may apply heat to the material. In some embodiments, the dryer moves the material while drying it by blowing heated air onto the material and / or rotating it on a conveyor or within the dryer. The heat source may be, additionally or alternatively, for example, an oven, a dryer, a heat jet, or an infrared source.

[0041] After the heat treatment, the UV-blocking composition can remain bound to the material over a long period of time. For example, the composition can remain bound to the material during 5 consecutive uses and / or during cleaning such as 0 or more washing cycles.

Examples

[0042] Experimental methods

[0043] Example 1

[0044] The uncolored 100% cotton fabric obtained from Test Fabrics LLC was immersed in an aqueous solution bath containing 1 wt% of tannic acid, a polyphenol compound. Subsequently, the fabric was taken out and placed in an aqueous solution bath containing 3 wt% of sodium caseinate, a protein capping agent, and immediately placed on a conveyor dryer and heated. The heating was carried out at a temperature of 150 °C until the fabric was completely dried. Visible changes were observed, and the color changed to light brown / yellow.

[0045] The ultraviolet transmittance of the fabric before and after treatment was measured in the range of 280 to 400 nm using a Shimadzu UV-2600i with an integrating sphere, and the ultraviolet protection factor (UPF) value was calculated according to the EN13758 method. Next, the treated fabric was washed in a commercial washing / dryer system according to the AATCC LP1 protocol using a standard AATCC 1993 detergent containing a fluorescent whitening agent, and the ultraviolet transmittance was measured. The results are shown in Table 1 below.

[0046]

Table 1

[0047] A photograph of the fabric is shown in Figure 6. The left is the untreated control fabric. The fabric in the center is yellowish after treatment. The fabric on the right is after treatment and washing, and a further beige discoloration is observed.

[0048] The results of the UPF spectrum are shown in Figure 5, comparing the ultraviolet transmittance of the untreated control sample and the treated fabric before and after washing. The top line is the control example with the highest transmittance. The middle line is the untreated treated fabric with a considerably lower transmittance. The bottom line has the lowest transmittance and is the treated fabric after washing.

[0049] Example 2

[0050] An uncolored cotton / polyester (approx. 50 / 50) fabric obtained from an outdoor supplies brand was immersed in an aqueous solution tank containing 0.8 wt% tannic acid, a polyphenol compound. Next, the fabric was dried in a conveyor dryer at a temperature of approximately 100°C. Further, this sample was placed in an aqueous solution tank containing 2.5 wt% casein protein capping agent and immediately placed on a conveyor dryer and heated. The heating was carried out at a temperature of 150°C until the fabric was completely dry. Next, the treated fabric was washed in a commercial washing / drying system according to the AATCC LP1 protocol using a standard AATCC 1993 detergent containing a fluorescent whitening agent.

[0051] As can be seen from the photograph shown in Figure 8, visible changes occurred due to the treatment. The left side is the control fabric. The fabric in the center is the treated fabric that has not been washed and is slightly beige compared to the control fabric. The fabric on the right is the treated fabric after washing and is more beige than the treated fabric. As a visible change, it was confirmed that the color of the fabric changed to a bright brown / yellow.

[0052] For the control and treated fabrics, the ultraviolet transmittance was measured in the range of 280 to 400 nm using a Shimadzu UV-2600i with an integrating sphere, and the UPF value was calculated according to the EN13758 method. The spectrum of the results shown in the graph in Figure 7 compares the ultraviolet transmittance of the untreated control sample (upper line) and the treated fabric that has not been washed (center line). The ultraviolet transmittance of the treated and washed fabric is the bottom line. The UPF results are shown in Table 2 below.

[0053]

Table 2

[0054] The results of Examples 1 and 2 show that the treatment process significantly reduced the ultraviolet transmittance and increased the UPF compared to the untreated materials. When the treated materials were washed, the color change further progressed, the transmittance further decreased, and the UPF further increased. This is presumably due to some additional reaction between the reactive sites on the UV blockers not bound by the capping agent and the components of the detergent, which is expected to stabilize over time. Thus, these results suggest that the capping agent did not prevent all interactions with the UV blockers, but the resulting discoloration was minor, indicating that the capping agent successfully protected the interactions with the UV blockers and reduced and minimized the resulting color change.

[0055] As used herein, the terms "substantially" or "generally" refer to a complete or nearly complete range or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is "substantially" or "generally" enclosed means that the object is either completely enclosed or nearly completely enclosed. The exact tolerance for deviation from absolute completeness may sometimes depend on the specific context. However, being nearly complete results in the same overall outcome as when absolute and complete completeness is achieved. The use of "substantially" or "generally" is equally applicable when used in a negative sense to mean a complete absence or near-complete absence of an action, characteristic, property, state, structure, item, or result. For example, an element that is "substantially free" or "generally free" of a certain element, combination, embodiment, or composition may actually contain such an element as long as its impact is not significant.

[0056] In the foregoing description, various embodiments of the present invention have been presented for purposes of illustration and description. These are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described in order to provide an illustration of the principles of the invention and its practical application, to enable those skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and changes, when interpreted in accordance with the scope permitted by justice, law, and equity, are within the scope of the invention as determined by the appended claims.

Claims

1. Sheet substrates containing synthetic, semi-synthetic, or natural fabrics or mixtures thereof, The ultraviolet absorbing chemical substance present in the substrate, A capping agent to which the aforementioned ultraviolet absorbing chemical substance is bound, UV-protective fabric, including...

2. The ultraviolet-protective fabric according to claim 1, wherein the ultraviolet-absorbing chemical substance comprises an organic acid, a protein, a flavonoid, or a polyphenol compound.

3. The ultraviolet-protective fabric according to claim 1, wherein the ultraviolet-absorbing chemical substance includes an aromatic acid.

4. The ultraviolet-protective fabric according to claim 1, wherein the ultraviolet-absorbing chemical substance comprises gallic acid, tannic acid, caffeic acid, dopamine, salicylic acid, or ferulic acid.

5. The ultraviolet-protective fabric according to claim 1, wherein the ultraviolet-absorbing chemical substance contains tannic acid.

6. The UV-protective fabric according to claim 1, wherein the capping agent comprises an alkylbenzene surfactant, a phenylethanoid, a monophenol, or a protein.

7. The UV-protective fabric according to claim 1, wherein the capping agent contains naturally derived protein.

8. The UV-protective fabric according to claim 7, wherein the aforementioned natural protein includes whey or casein.

9. The ultraviolet-protective fabric according to claim 1, including clothing configured for a user to wear.

10. The ultraviolet protective fabric according to claim 1, having a coverage rate of 97% to 100%.

11. The UV-protective fabric according to claim 1, wherein the sheet substrate comprises an organic porous material.

12. The UV-protective fabric according to claim 11, wherein the organic porous material further comprises inorganic components in the form of nanoparticles, coatings, or fibers.

13. A method for manufacturing ultraviolet-protective fabric, a. A step of coating a porous material with an ultraviolet-absorbing organic compound in a solution and diffusing the ultraviolet-absorbing organic compound into the porous material, b. A step of drying the porous material to which the ultraviolet-absorbing organic compound solution has been applied, thereby bonding the compound to the fibers on the surface and inside the material, A manufacturing method that includes this.

14. The method according to claim 13, wherein drying the porous material includes heating the porous material.

15. The method according to claim 13, wherein the ultraviolet-absorbing organic compound comprises tannic acid.

16. After step a, c. The method according to claim 13, further comprising the step of applying a capping agent in a solution to the porous material and diffusing the capping agent into the porous material.

17. The method according to claim 16, wherein the capping agent comprises a naturally derived casein salt.

18. The method according to claim 16, wherein step c is performed before step b.

19. The method according to claim 16, wherein step c is performed after step b, and the method further comprises the step of drying the porous material having the coated capping agent to bond the capping agent to the ultraviolet absorbing compound.

20. The method according to claim 16, wherein the porous material includes a fabric.

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